Java Basic Programs

Explore our extensive repository of Java programming examples. Java is a versatile, object-oriented programming language used for building enterprise-scale applications, mobile apps (Android), and web services. Below, you will find practical Java snippets covering topics like OOP principles, collections framework, exception handling, and multithreading. Whether you are preparing for an interview or learning Java for the first time, these code snippets will enhance your problem-solving skills.

Code Snippet


class Prog1
{
public static void main(String args[])
{
    System.out.println("Hello Java World!");
    System.out.println("Telutu IT Tutorials");
    System.out.println("Ongole");    
}
}

Code Snippet


import java.util.*;
class Prog2
{
    public static void main(String args[])
    {
        Scanner scanner = new Scanner(System.in);
        int a,b,c;
        System.out.println("Enter a,b values");
        a=scanner.nextInt();
        b=scanner.nextInt();
        c=a+b;
        System.out.println("A=" + a);
        System.out.println("B=" + b);
        System.out.println("Sum=" + c);
    }
}

Code Snippet


import java.util.*;
class Prog3
{
    public static void main(String args[])
    {
        Scanner scanner=new Scanner(System.in);
        float r,area,pi=3.1416f;
        System.out.println("Enter radius value");
        r=scanner.nextFloat();
        area=pi*r*r;
        System.out.println(r + " Area is " + area);
    }
}

Control Statements

Code Snippet


import java.util.*;
class Prog1
{
    public static void main(String args[])
    {
        int m,p,c,avg;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter m,p,c values");
        m=in.nextInt();
        p=in.nextInt();
        c=in.nextInt();
        avg=((m+p+c)/3);
        if(m>34 && c>34 && p>34)
        {
            if(avg>34 && avg<50)
            {
             System.out.println("Ordianary");   
            }
            else if(avg>=50 && avg<60)
            {
            System.out.println("Second class");
            }
            else if(avg>=60 && avg<75)
            {
            System.out.println("First Class");
            }
            else if(avg>=75 && avg<=100)
            {
                System.out.println("Distinction");
            }
            else if(avg>100)
            {
                System.out.println("Given Marks is Wrong");
            }

        }
        else
        {
            if(m<35)
            System.out.print("Maths  ");
            if(p<35)
            System.out.print("Phy ");
            if(c<35)
            System.out.print("Che ");
            System.out.print(" Failed");
        }
    }
}

Code Snippet



import java.util.Scanner;
class Prog2
{
    public static void main(String args[])
    {
    int n,i;
    Scanner in=new Scanner(System.in);
    System.out.println("Enter n value");
    n=in.nextInt();
    i=1;
    while(i<=10)
    {
        System.out.println(n + "X" + i + "=" + n*i);
        i++;
    }
    }
    
}

Code Snippet


/*
1
12
123
1234
12345
*/
import java.util.*;
class Prog3
{
    public static void main(String args[])
    {
        int n;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter n value");
        n=in.nextInt();
        for(int i=1;i<=n;i++)
        {
            for(int j=1;j<=i;j++)
            {
                System.out.print(j + " ");
            }
            System.out.println("");
        }
        for(int i=n-1;i>=1;i--)
        {
            for(int j=1;j<=i;j++)
            {
                System.out.print(j + " ");
            }
            System.out.println("");
        }

    }
}

Code Snippet


import java.util.*;
class Prog4
{
    public static void main(String args[])
    {
        int amount,sum=0;
        Scanner in=new Scanner(System.in);
        do
        {
            System.out.println("Enter Amount");
            amount=in.nextInt();
            if(amount>0)
            {
                sum=sum+amount;
                System.out.println("Cumilative Amount is :" + sum);
            }
        }while(amount>0);
        System.out.println("The Total Amount  is " + sum);
    }
}

Code Snippet


import java.util.*;
class Prog5
{
    public static void main(String args[])
    {
        int a,b,c;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter a,b values");
        a=in.nextInt();
        b=in.nextInt();
        do{
        System.out.println("1.Addition");
        System.out.println("2.Subtraction");
        System.out.println("3.Multiplication");
        System.out.println("4.Division");
        System.out.println("5.Modulus");
        System.out.println("6.Exit");
        System.out.println("Enter Your Choice ");
        c=in.nextInt();
        switch(c)
        {
            case 1:
            System.out.println("A+B=" + (a+b));
            break;
            case 2:
            System.out.println("A-B=" + (a-b));
            break;
            case 3:
            System.out.println("AXB=" + (a*b));
            break;
            case 4:
            System.out.println("A/B=" + (a/b));
            break;
            case 5:
            System.out.println("A%B=" + (a%b));
            break;
            default:
            System.out.println("Your Exit");
        }
        }while(c<=5);

    }
}

Arrays

Code Snippet


import java.util.*;
class Prog1
{
    public static void main(String args[])
    {
        /*int a[],n,i;*/
        int[] a;
        int n,i;

        Scanner in=new Scanner(System.in);
        System.out.println("Enter array size");
        n=in.nextInt();
        a=new int[n]; //Re initilization array
        System.out.println("Enter " + n + " Elements");
        for(i=0;i<n;i++)
        {
            a[i]=in.nextInt();
        }
        System.out.println("The Elements are");
        for(i=0;i<n;i++)
        {
            System.out.print(a[i] + " ");
        }
        System.out.println("\nThe Elements in Reverse is ");
        for(i=n-1;i>=0;i--)
        {
            System.out.print(a[i] + " ");
        }
    }
}

Code Snippet


import java.util.*;
class Prog2
{
    public static void main(String args[])
    {
        int a[][],r,c,i,j;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter r,c values");
        r=in.nextInt();
        c=in.nextInt();
        a=new int[r][c];
        System.out.println("Enter " + r + "X" + c + " Matrix values");
        for(i=0;i<r;i++)
        {
            for(j=0;j<c;j++)
            {
                a[i][j]=in.nextInt();
            }
        }
        System.out.println("The Matrix is ");
        for(i=0;i<r;i++)
        {
            for(j=0;j<c;j++)
            {
                System.out.print(a[i][j] + " ");
            }
            System.out.println("");
        }
    }
}

Functions

Code Snippet


//No Arguments Pass and No Return values
import java.util.*;
class Prog1
{
    public static void area()
    {
        float r,pi=3.1416f,a;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter radius value");
        r=in.nextFloat();
        a=pi*r*r;
        System.out.println(r + " Area is " + a);
    }
    public static void main(String args[])
    {
        int n,i;
       Scanner in=new Scanner(System.in);
        System.out.println("Enter n value");
        n=in.nextInt();
        for(i=1;i<=n;i++)
        {
            area();
        }
    }
}

Code Snippet


import java.util.*;
class Prog2
{
    public static void area(float r)
    {
        float pi=3.1416f,a;
        a=pi*r*r;
        System.out.println(r + " Area is " + a);
    }
    public static void main(String args[])
    {
        int n,i;
        float r;
       Scanner in=new Scanner(System.in);
        System.out.println("Enter n value");
        n=in.nextInt();
        for(i=1;i<=n;i++)
        {
            System.out.println("Enter Radius value");
            r=in.nextFloat();
            area(r);
        }
    }
}

Code Snippet



import java.util.*;
class Prog3
{
    public static float area(float r)
    {
        float pi=3.1416f,a;
        a=pi*r*r;
        return(a);
    }
    public static void main(String args[])
    {
        int n,i;
        float r,a;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter n value");
        n=in.nextInt();
        for(i=1;i<=n;i++)
        {
            System.out.println("Enter Radius value");
            r=in.nextFloat();
            a=area(r);
            System.out.println(r + " Area is " + a);
        }
    }
}

Code Snippet


// No Arguments Pass But  Return values
import java.util.*;
class Prog4
{
    public static float area()
    {
        float r,pi=3.1416f,a;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter Radius value");
        r=in.nextFloat();
        a=pi*r*r;
        System.out.print(r);
        return(a);
    }
    public static void main(String args[])
    {
        int n,i;
        float a;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter n value");
        n=in.nextInt();
        for(i=1;i<=n;i++)
        {
            a=area();
            System.out.println(" Area is " + a);
        }
    }
}

Functions Overloading

Code Snippet



/*
Functions Overloading ?
The function name is the common and the parameters is different is called a 
functions overloading
*/

import java.util.*;
class Prog1
{
    public static int sum(int a,int b)
    {
        return(a+b);
    }
    public static int sum(int a,int b,int c)
    {
        return(a+b+c);
    }
    public static int sum(int a,int b,int c,int d)
    {
        return(a+b+c+d);
    }
    public static float sum(int a,float b)
    {
        return(a+b);
    }
    public static float sum(float a,int b)
    {
        return(a+b);
    }
    public static float sum(float a,float b)
    {
        return(a+b);
    }
    public static void main(String args[])
    {
    int a,b,c,d;
    float e,f;
    Scanner in=new Scanner(System.in);
    System.out.println("Enter any four Integers");
    a=in.nextInt();
    b=in.nextInt();
    c=in.nextInt();
    d=in.nextInt();
    System.out.println("Enter any two Float numbers");
    e=in.nextFloat();
    f=in.nextFloat();
    System.out.println("A+B=" + sum(a,b));
    System.out.println("A+B+C=" + sum(a,b,c));
    System.out.println("A+B+C+D=" + sum(a,b,c,d));
    System.out.println("A+E=" + sum(a,e));
    System.out.println("E+A=" + sum(e,a));
    System.out.println("E+F=" + sum(e,f));
    }
}

OOPS

Code Snippet


/*
What is the Class ?
The combination state and behaviour of the object is called class
What is the Object ?
A instance of the class is called object
*/
import java.util.*;
class Student
{
    int code;
    String name;
    String course;
    public void setStudent(int intcode,String strname,String strcourse)
    {
        code=intcode;
        name=strname;
        course=strcourse;
    }
    public void showStudent()
    {
        System.out.println("Code   : " +code);
        System.out.println("Name   : " +name);
        System.out.println("Course : " +course);
    }
}
class Prog1
{
    public static void main(String args[])
    {
        Student student1=new Student();
        int code;
        String name,course;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter Code Name Course");
        code=in.nextInt();
        name=in.next();
        course=in.next();
        student1.setStudent(code,name,course);
        Student student2=new Student();
        System.out.println("Enter Code Name Course for Student 1");
        code=in.nextInt();
        name=in.next();
        course=in.next();
        student2.setStudent(code,name,course);
        student1.showStudent();
        student2.showStudent();
    }
}

Code Snippet


/*if your using private keyword with in the class memebers we can't 
access out side of the class other then private it can access*/

import java.util.*;
class Person
{
    int code;
    String name;
    String course;
}
class Prog2
{
    public static void main(String args[])
    {
        Person person=new Person();
        Scanner in=new Scanner(System.in);
        System.out.println("Enter Code Name Course");
        person.code=in.nextInt();
        person.name=in.next();
        person.course=in.next();
        System.out.println("Code : " + person.code);
        System.out.println("Name : " + person.name);
        System.out.println("Course : " + person.course);
    }
}

Constructors

Code Snippet



/*
What is the Constructor ?
The constructor can initialize the class members
note: whenever we instantiated the class then automatically the constructor
executed

Rules:
    1)The constructor name must be a class name
    2)No return type in constructors
Types of Constructors:
    1)Default constructor(With out parameters or arguments)
    2)Parameterised constructor( With parameters or arguments)

Overloading Construrctor:
    if you are using default constructor and parameterised constructor
    using a single class i.e overloading construcotrs

*/

import java.util.*;
class Employee
{
    int code;
    String name;
    String desig;
    Employee()
    {
        code=100;
        name="SrinivasaRao.K";
        desig="Engg";
    }
    public void setEmployee(int code,String name,String desig)
    {
        this.code=code;
        this.name=name;
        this.desig=desig;
    }
    public void showEmployee()
    {
        System.out.println("Code  : " + code);
        System.out.println("Name  : " + name);
        System.out.println("Desig : " + desig);
    }
}
class Prog1
{
public static void main(String args[])
{
    int code;
    String name,desig;
    Scanner in=new Scanner(System.in);
    Employee employee=new Employee();
    employee.showEmployee();
    
    System.out.println("Enter code name desig");
    code=in.nextInt();
    name=in.next();
    desig=in.next();
 
    employee.setEmployee(code,name,desig);
    employee.showEmployee();
}
}

Code Snippet


/*Default Contructor and Parameterised Constructor*/
import java.util.*;
class Employee
{
    int code;
    String name;
    String desig;
    Employee()//default constructor
    {
        code=100;
        name="SrinivasaRao.K";
        desig="Engg";
    }
    Employee(int code,String name,String desig)//parameterised constructor
    {
        this.code=code;
        this.name=name;
        this.desig=desig;
    }
    public void setEmployee(int code,String name,String desig)
    {
        this.code=code;
        this.name=name;
        this.desig=desig;
    }
    public void showEmployee()
    {
        System.out.println("Code  : " + code);
        System.out.println("Name  : " + name);
        System.out.println("Desig : " + desig);
    }
}
class Prog2
{
public static void main(String args[])
{
    int code;
    String name,desig;
    Scanner in=new Scanner(System.in);
    System.out.println("Enter code name desig");
    code=in.nextInt();
    name=in.next();
    desig=in.next();
    Employee employee=new Employee();//default constructor
    employee.showEmployee();
    employee.setEmployee(code,name,desig);
    employee.showEmployee();
    Employee employee1=new Employee(102,"Durrga","CSC");
    //parameterised constructor
    employee1.showEmployee();
    employee1.setEmployee(code,name,desig);
    employee1.showEmployee();
}
}

Inheritance

Code Snippet


/*
What is Inheritance?
A relation between the Parent class and Child class is called inheritance
or
A Mechanisam between the Base class and derived class is called inhertinace

Single Inheritance
*/
import java.util.*;
class Father
{
    int fcode;
    String fname;
    Father(int fcode,String fname)
    {
        this.fcode=fcode;
        this.fname=fname;
    }

}
class Child extends Father
{
int code;
String name;
Child(int fcode,String fname,int code,String name)
{
    super(fcode,fname);
    this.code=code;
    this.name=name;
}
void showDetails()
{
    System.out.println("Father Code " + fcode);
    System.out.println("Father Name " + fname);
    System.out.println("Child Code " + code);
    System.out.println("Child Name " + name);

}
}

class Prog1
{
    public static void main(String args[])
    {
        int fcode,code;
        String fname,name;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter Father Code and Name");
        fcode=in.nextInt();
        fname=in.next();
        System.out.println("Enter Child Code and Name");
        code=in.nextInt();
        name=in.next();
        Child child =new Child(fcode,fname,code,name);
        child.showDetails();
    }
}

Code Snippet


/*Multilevel Inheritance*/
import java.util.*;
class GFather
{
    int gcode;
    String gname;
    GFather(int gcode,String gname)
    {
        this.gcode=gcode;
        this.gname=gname;
    }

}
class Father extends GFather
{
    int fcode;
    String fname;
    Father(int gcode,String gname,int fcode,String fname)
    {
        super(gcode,gname);
        this.fcode=fcode;
        this.fname=fname;
    }

}
class Child extends Father
{
int code;
String name;
Child(int gcode,String gname,int fcode,String fname,int code,String name)
{
    super(gcode,gname,fcode,fname);
    this.code=code;
    this.name=name;
}
void showDetails()
{
    System.out.println("GFather Code " + gcode);
    System.out.println("GFather Name " + gname);
    System.out.println("Father Code " + fcode);
    System.out.println("Father Name " + fname);
    System.out.println("Child Code " + code);
    System.out.println("Child Name " + name);

}
}

class Prog2
{
    public static void main(String args[])
    {
        int gcode,fcode,code;
        String gname,fname,name;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter GFather Code and Name");
        gcode=in.nextInt();
        gname=in.next();
        System.out.println("Enter Father Code and Name");
        fcode=in.nextInt();
        fname=in.next();
        System.out.println("Enter Child Code and Name");
        code=in.nextInt();
        name=in.next();
        Child child =new Child(gcode,gname,fcode,fname,code,name);
        child.showDetails();
    }
}

Code Snippet


/*Hirarchical Inheritance*/
import java.util.*;
class Father 
{
    int fcode;
    String fname;
    Father(int fcode,String fname)
    {
        this.fcode=fcode;
        this.fname=fname;
    }

}
class Child1 extends Father
{
int code;
String name;
Child1(int fcode,String fname,int code,String name)
{
    super(fcode,fname);
    this.code=code;
    this.name=name;
}
void showDetails()
{
    System.out.println("Father Code " + fcode);
    System.out.println("Father Name " + fname);
    System.out.println("Child Code " + code);
    System.out.println("Child Name " + name);

}
}
class Child2 extends Father
{
int code;
String name;
Child2(int fcode,String fname,int code,String name)
{
    super(fcode,fname);
    this.code=code;
    this.name=name;
}
void showDetails()
{
    System.out.println("Father Code " + fcode);
    System.out.println("Father Name " + fname);
    System.out.println("Child Code " + code);
    System.out.println("Child Name " + name);

}
}

class Prog3
{
    public static void main(String args[])
    {
        int fcode,code1,code2;
        String fname,name1,name2;
        Scanner in=new Scanner(System.in);
        System.out.println("Enter Father Code and Name");
        fcode=in.nextInt();
        fname=in.next();
        System.out.println("Enter Child1 Code and Name");
        code1=in.nextInt();
        name1=in.next();
        System.out.println("Enter Child2 Code and Name");
        code2=in.nextInt();
        name2=in.next();
        Child1 child1 =new Child1(fcode,fname,code1,name1);
        Child2 child2 =new Child2(fcode,fname,code2,name2);
        child1.showDetails();
        child2.showDetails();
    }
}

Abstract Classes

Code Snippet


/*
Polymorphisam
method overridding
multiple Inheritance

Abstract Classes
The abstract class inside can accept ordinary methods
                                      ordinary variables
                                      Abstract methods(Declaration only)
                                      Final variables
Note:Every abstract class before we must type abstract keyword

Interfaces
No need of to abstract key bofore the class name why becuase by default
all Interfaces are declared as abstract Classes
The interfaces can accept Static final varibales and
abstract methods(Declaration only)
*/
import java.util.*;
abstract class Bike
{
  abstract void getBenifit();
}
class Honda extends Bike
{
void getBenifit()
{
System.out.println("Honda Running Smoothly");
}
}
class Bajaj extends Bike
{
void getBenifit()
{
System.out.println("Bajaj  Gives More Milage");
}
}
class Bullet extends Bike
{
void getBenifit()
{
System.out.println("Bullet is More Power like (350 cc)");
}
}

class Prog1
{
public static void main(String args[])
{
int choice;
Scanner in=new Scanner(System.in);
do
{
System.out.println("Enter Your Choice(Honda-1,Bajaj-2,Bullet-3,Others-[4-9])");
choice=in.nextInt();
if(choice==1)
{
 Bike honda = new Honda();
 honda.getBenifit();
}
else if(choice==2)
	 {
	 Bike baja= new Bajaj();
	 baja.getBenifit();
	 }
	else if(choice==3)
		{
		 Bike bullet= new Bullet();
		 bullet.getBenifit();
		}
		else
		{
		System.out.println("Your Selection is out Range");
		}

}while(choice>0 && choice<=3);
}
}

Code Snippet


import java.util.*;
abstract class Area
{
  String cname;
  abstract float getArea(float param1,float param2);
  public void showName()
  {
  cname="KKCC INFO SYSTEMS";
  System.out.println(cname);
  }
}
class Rectangle extends Area
{
float getArea(float  l,float w)
{
return(l*w);
}
}
class Circle extends Area
{
float getArea(float r,float r1)
{
return(3.1416f*r*r);
}
}

class Prog2
{
public static void main(String args[])
{
Scanner in=new Scanner(System.in);
 Area rectangle = new Rectangle();
 Area circle= new Circle();
float a,r;
int l,w;
System.out.println("Enter l,w values");
l=in.nextInt();
w=in.nextInt();
a= rectangle.getArea(l,w);
rectangle.showName();
System.out.println("Rectangle Area = " + a);
System.out.println("Enter Radius value");
r=in.nextFloat();
circle.showName();
a=circle.getArea(r,0f);
System.out.println("Circle Area = " +a);
}
}

Interfaces

Code Snippet


import java.util.*;
// interfaces are allowed only static final variables and abstract methods
// all interfaces are declared by default as abstract
interface  Area
{
public float getArea(float l,float w);
public static final String objname="KKCC INFO SYSTEMS";
}
class Rectangle  implements Area
{
public float getArea(float  l,float w)
{
return(l*w);
}
}
class Circle  implements Area
{
public float getArea(float r,float r1)
{
return(3.1416f*r*r);
}
}
class Square implements Area
{
public float getArea(float l,float w)
{
return(l*w);
}
}
class Prog3
{
public static void main(String args[])
{
Scanner in=new Scanner(System.in);
 Area rectangle = new Rectangle();
 Area circle= new Circle();
 Area square=new Square();
float l,w,r,a;

System.out.println("Enter l,w values");
l=in.nextFloat();
w=in.nextFloat();
a= rectangle.getArea(l,w);
System.out.println("Rectangle Area = " + a);
System.out.println("Object Name=" + rectangle.objname);

System.out.println("Enter Radius values");
r=in.nextFloat();
a=circle.getArea(r,0.0f);
System.out.println("Circle Area = " + a);
System.out.println("Object Name=" + circle.objname);

System.out.println("Enter Side values");
l=in.nextFloat();
a=square.getArea(l,l);
System.out.println("Square Area ="+ a);
System.out.println("Object Name=" + square.objname);
}
}

Code Snippet



interface Comp
{
public static final String objname="KKCC INFO SYSTEMS";
}
interface  Area extends Comp
{
public float getArea(float a,float b);
}

class Rectangle  implements Area
{
public float getArea(float  l,float w)
{
return(l*w);
}
}
class Circle  implements Area
{
public float getArea(float r,float r1)
{
return(3.1416f*r*r);
}
}
class Prog4
{
public static void main(String args[])
{
Area rectangle = new Rectangle();
Area circle= new Circle();
float a;
a= rectangle.getArea(5,6);
System.out.println("Rectangle Area = " + a);
System.out.println("Object Name=" + rectangle.objname);
a=circle.getArea(4.56f,0f);
System.out.println("Circle Area = " + a);
System.out.println("Object Name=" + circle.objname);
}
}

Built-in Functions

Code Snippet


//String Functions Example
import java.util.*;
class Prog1
{
public static void main(String args[])
{
String name;
Scanner in=new Scanner(System.in);
int p;
name="Hellow How Are You";
System.out.println("Enter Which position character you want print");
p=in.nextInt();
System.out.println(name.charAt(p));
System.out.println(name.compareTo("hellow How Are You"));
System.out.println(name.compareToIgnoreCase("HELLOW HOW ARE YOU"));
System.out.println(name.concat(" Srinivas"));
System.out.println("Kunchala, ".concat(name));
System.out.println(name.toLowerCase());
System.out.println(name.toUpperCase());
}
}

Code Snippet


import java.util.*;
class Prog2
{
public static void main(String args[])
{
String pwd,rpwd;
int cnt,r;
cnt=1;
Scanner in=new Scanner(System.in);
do {
  System.out.println("Enter Password  : ");
  pwd=in.next();
  System.out.println("Re-Type Password : ");
  rpwd=in.next();
  r=pwd.compareTo(rpwd);
  if(r==0)
  {
    System.out.println("Passwors is Success");
  }
  else
  {
    System.out.println("Password Not Match Try Again !");
  }
  cnt+=1;
} while (r!=0 && cnt<=3);

if(r!=0 && cnt>0)
{
  System.out.println("Your Attempts is completed. Try again after 30 Minutes!");
}
}
}

Code Snippet


class Prog3
{
  public static void main(String args[])
  {
    String name="SrinivasaRao",name1="   SrinivasaRao   ";
    System.out.println(name.length());
    System.out.println(name.charAt(0));
    System.out.println(name.indexOf('S'));
    System.out.println(name.substring(3));
    System.out.println(name.substring(3,6));
    System.out.println(name.toLowerCase());
    System.out.println(name.toUpperCase());
    System.out.println("Rama is a good boy".replace("good","bad"));
    System.out.println(name.equals("SrinivasaRao"));
    System.out.println(name.equalsIgnoreCase("srinivasarao"));
    System.out.println(name.concat(" Garu"));
    System.out.println(name1.trim());
    System.out.println(name.endsWith("Rao"));
    System.out.println(name.startsWith("Sri"));

  }
}

Code Snippet



//String Tokens
import java.util.Scanner;
import java.util.StringTokenizer;

public class Prog4 {
    public static void main(String args[]) {
        String name;
        Scanner in = new Scanner(System.in);
        name = in.nextLine();
        StringTokenizer st = new StringTokenizer(name);
        while (st.hasMoreTokens()) {
            System.out.println(st.nextToken());
        }

    }
}

Code Snippet


/*Math Functions*/

class Prog5
{
  public static void main(String args[])
  {
    int a = 28,b= 4;
    double r;
    System.out.println("Maximum number of a and b is: " + Math.max(a, b));
    r= Math.sqrt(b);
    System.out.println("Square root of b is: " +r);
    System.out.println("Power of x and b is: " + Math.pow(a, b));
    System.out.println("Logarithm of a is: " + Math.log(a));
    System.out.println("Logarithm of b is: " + Math.log(b));
    System.out.println("log10 of a is: " + Math.log10(a));
    System.out.println("log10 of b is: " + Math.log10(b));
    System.out.println("log1p of a is: " + Math.log1p(a)); // return the log of x + 1
    System.out.println("exp of a is: " + Math.exp(a));
    System.out.println("expm1 of a is: " + Math.expm1(a));  // return (a power of 2)-1

  }
}

Code Snippet


class Prog6
{
  public static void main(String args[])
  {
    double angle=30;
    System.out.println("Degree to Radiuns is: " + Math.toRadians(angle));// converting values to radian
    System.out.println("Degree to Radiuns is: " + Math.round(Math.toRadians(angle)));// converting values to radian
    System.out.println("Sine value of a is: " + Math.sin(angle));
    System.out.println("Cosine value of a is: " +Math.cos(angle));
    System.out.println("Tangent value of a is: " +Math.tan(angle));
    System.out.println("A Sine value of a is: " +Math.asin(angle));
    System.out.println("A Cosine value of a is: " +Math.acos(angle));
    System.out.println("A Tangent value of a is: " +Math.atan(angle));
    System.out.println("H Sine value of a is: " +Math.sinh(angle));
    System.out.println("H Cosine value of a is: " +Math.cosh(angle));
    System.out.println("H Tangent value of a is: " +Math.tanh(angle));

  }
}

Code Snippet



import java.text.DecimalFormat;
class Prog7
{
	public static DecimalFormat df=new DecimalFormat("00.000");
  public static void main(String args[])
  {
    double d=456.55656;

    System.out.println("Absolute value of a is: " + Math.abs(-456));// converting values to radian
    System.out.println("Max value of a is: " +Math.max(45,56));
    System.out.println("Min value of a is: " +Math.min(45,56));
    System.out.println("SQrt value of a is: " +Math.sqrt(12));
    System.out.println("Cubic Root value of a is: " +Math.cbrt(12));
    System.out.println("power value of a is: " +Math.pow(2,2));
    System.out.println("sign value of a is: " +Math.signum(-456));
    System.out.println("Ceil value of a is: " +Math.ceil(45.56f));
    System.out.println("Floor value of a is: " +Math.floor(45.56f));
	System.out.println("Round" + df.format(d));
  }
}

Vectors

Code Snippet


import java.util.*;
class Prog1
{
public static void main(String args[])
{
Scanner in=new Scanner(System.in);
int i,n,p;
String name[],element;
Vector vector=new Vector();
System.out.println("Enter n vaule");
n=in.nextInt();
System.out.println("Enter " + n + " Elements");
for(i=0;i<n;i++)
{
  element=in.next();
  vector.addElement(element);
}

for(i=0;i<vector.size();i++)
{
System.out.println((i + 1) + ")" + vector.elementAt(i));
}

System.out.println("Which position you want add element");
p=in.nextInt();
element=in.next();
vector.insertElementAt(element,p);

System.out.println("After Inserting  Elements are");
for(i=0;i<vector.size();i++)
{
System.out.println((i + 1) + ")" + vector.elementAt(i));
}
System.out.println("Which position you want remove element");
p=in.nextInt();
vector.removeElementAt(p);
System.out.println("After Removing  Elements are");
for(i=0;i<vector.size();i++)
{
System.out.println((i + 1) + ")" + vector.elementAt(i));
}
name=new String[vector.size()];
vector.copyInto(name);
vector.removeAllElements();
System.out.println("The String elements are");
for(i=0;i<name.length;i++)
{
System.out.println((i+1) + ")" + name[i]);
}
}
}

Multi Thread

Code Snippet


/*
What is multithread ?
multithread is a separate program.
A Single processor can do the multple programs simultaneously.
it executes concurrently or parallely depends upon the system speed.
In Operating system we are calling Multitasking
In Programming Languages we are calling Multithrading

*/
class Prog1 extends Thread
{
public void run()
{
    try
    {
        System.out.println("\nMy First Thread is Started");
        for(int i=1;i<=5;i++)
        {
            System.out.println("\ni=" + i);
            if(i==1 || i==3)
            {
            sleep(1000);
            }
        }
        System.out.println("\nThread is Completed");
    }
    catch(Exception e)
    {
        System.out.println(e);
    }
}
public static void main(String args[])
{
Prog1  mt=new Prog1 ();
mt.start();
System.out.println("The Above thread is started");
}

}

Code Snippet



class Count extends Thread {
  Count() {
    start();
  }

  public void run() {
    try {
      for (int i = 0; i < 10; i++) {
        System.out.println("Printing the count " + i);
        Thread.sleep(1000);
      }
    } catch (InterruptedException e) {
      System.out.println("my thread interrupted");
    }
    System.out.println("Thread run is Complete");
  }
}

class Prog2 {
  public static void main(String args[]) {
    Count cnt = new Count();
    // cnt.start();
    try {
      while (cnt.isAlive()) {
        System.out.println("Thread will be alive till the child thread is live");
        Thread.sleep(3000);
      }
    } catch (InterruptedException e) {
      System.out.println("Main thread interrupted");
    }
    System.out.println("Main thread's run is over");
  }
}

Code Snippet



class MultiThread implements Runnable
/*class MultiThread  extends Thread*/
{
public void run()
{
try
{
System.out.println("Thread is in running Start.");
for(int i=1;i<=5;i++)
{
System.out.println("I=" + i);
Thread.sleep(1000);
}
}
catch(Exception e)
{
System.out.println(e);
}
}
}
class Prog3
{
public static void main(String args[])
{
MultiThread mt=new MultiThread();
Thread newobj =new Thread(mt);
/*MultiThread newobj=new MultiThread();*/
newobj.start();
 }
}

Code Snippet



class Count implements Runnable
//class Count extends Thread
{
Thread mythread=new Thread(this, "Child Thread");
Count()
{
mythread.start();
}
   public void run()
   {
      try
      {
        for (int i=0 ;i<10;i++)
        {
          System.out.println("Printing the count " + i);
          Thread.sleep(1000);
        }
     }
     catch(InterruptedException e)
     {
        System.out.println("my thread interrupted");
     }
     System.out.println("mythread run is over" );
   }
}
class Prog4
{
    public static void main(String args[])
    {
       Count cnt = new Count();
      //  Thread mythread=new Thread(cnt);
      //  mythread.start();
       try
       {
          while(cnt.mythread.isAlive())
          {
            System.out.println("Thread will be alive till the child thread is live");
            Thread.sleep(3000);
          }
       }
       catch(InterruptedException e)
       {
          System.out.println("Thread interrupted");
       }
       System.out.println("Thread run is over" );
    }
}

Code Snippet


class ThreadA extends Thread
{
public void run()
{  
try
{
System.out.println("\nThread A is running Start.");
for(int i=1;i<=5;i++)
{
System.out.println("\nThread A=" + i);
}
System.out.println("\nThread A Closed");
}
catch(Exception e)
{
    System.out.println(e);
}
}
}
class ThreadB extends Thread
{
public void run()
{
try
{
System.out.println("\nThread B is running Start.");
for(int i=1;i<=5;i++)
{
System.out.println("\nThread B=" + i);
}
System.out.println("\nThread B Closed");
}
catch(Exception e)
{
}
}
}
class ThreadC extends Thread
{
public void run()
{
try
{
System.out.println("\nThread C is running Start.");
for(int i=1;i<=5;i++)
{
System.out.println("\nThread C=" + i);
}
System.out.println("\nThread C Closed");
}
catch(Exception e)
{
}
}
}
class Prog5
{
public static void main(String args[])
{
try
{
ThreadA a=new ThreadA();
ThreadB b=new ThreadB();
ThreadC c=new ThreadC();
a.setPriority(Thread.MIN_PRIORITY);
b.setPriority(Thread.MAX_PRIORITY);
c.setPriority(Thread.NORM_PRIORITY);
System.out.println(a.getPriority());
System.out.println(b.getPriority());
System.out.println(c.getPriority());
a.start();
b.start();
c.start();
}
catch(Exception ex)
{
System.out.println(ex);
}
}
}

Conclusion & Next Steps

We hope these Java programs have helped you understand core Object-Oriented concepts and syntax. The best way to learn Java is by doing, so we encourage you to copy these snippets into your IDE, modify them, and see how they behave. Keep exploring more complex data structures to hone your skills.