Loop Statement In Java:-

It is used to print large statement of data using single repeatable block.Loop is also called control Structure because it can control repeated data using condition.

Type of Control Structure:-

1 Entry Control:-

   First Check Condition Then Execute Statement ,

   Example of Entry Control:-

   1.1 While Loop:-

         init;
         while(condition)
        {
                 statement;
                 increment;

         }
 

 WAP to calculate factorial of any entered number using complete expression?

5  :-  5*4*3*2*1=120
     public class HelloWorld{

     public static void main(String []args){
       
         int num=8;
         int i=num,f=1;
         String s="";
         while(i>1)
         {
             s=s+i+"*";
             f=f*i;
             i=i-1;
              
         }
        System.out.println(s+"1="+f);
     }
}

WAP to print 1 to 5 and 5 to 1 using single while loop?

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2
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5
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2
1

public class Main
{
    public static void main(String[] args) {
        int i=1;
        while(i<=10)
        {
            if(i<=5)
            System.out.println(i);
            else
            System.out.println(11-i);
           
            i++;
           
        }
    }
}

1.2 For Loop

using this we will implement all sub-statement using single statement;

for (init; condition; iteration)
{
       statement;
}

it provide simple syntax structure as compare to while loop.

for(int i=1;i<=10;i++)
{
       System.out.println(i);
}

WAP to check prime number ?
public class Main
{
    public static void main(String[] args) {
    int num=6,i;
    for(i=2;i<num;i++)
    {
       
        if (num%i==0)
            break;
    }
    if(num==i)
    {
         System.out.println("prime")  ; 
    }
    else
    {
         System.out.println("not prime")  ; 
    }
}
}

ASSIGNMENT:-

1)  WAP to print fibonacci series using expression?

2) WAP to reverse pin code and find max digit?

3) WAP to calculate square and cube of one digit positive number?



2 Exit Control:-

First Execute Statement Then Check Condition.

init;
do
{
    Statement;
    Increment;

}while(condition);


WAP to print table of any entered number with complete expression?

class TableExample
{
   public static void main(String args[])
   {
       int num=5;
       int i=1;
       do
       {
        System.out.println(num+"*"+i+" = "+(num*i));
        i=i+1; 
         
       }while(i<=10);       


   }


}



Note:-  When we want to create infinite loop in java then we always prefer while loop ?

while(true)
{
      statement;
       if(condition)
        false;

}


WAP to display menu option using "YES",,"Cancel" ,when  user press y then loop will be continue and when user press c then loop will be exit or terminated?

import java.util.Scanner;
class TableExample
{
   public static void main(String args[])
   {
       Scanner sc = new Scanner(System.in);
       while(true)
       {
      System.out.println("Prees y for continue");
      System.out.println("press n for cancellation");
      char ch;
      ch=sc.next().charAt(0);
      switch(ch)
      {
        case 'y':
        System.out.println("Yes");
        break;
        case 'n':
        System.out.println("no");
        System.exit(0);         
      }
         
       }     


   }


}