Java Loops

In Java we have three types of loops.We use loops in programming whenever we need
to execute the same statement several times.

• while loop
• do while loop
• for loop

while Loop

syntax

while(expression)
{
   statement(s);
}
The conditional expression must return a boolean value.The block inside while loop will be executed when it gets a true value of the expression.After execution of the inside block it rechecks the conditional expression.
Whenever it gets a false value of the expression it stops execution.
break statement is also used to get out of the loop.

do while Loop

do while syntax
do{

statement(s);

}while(expression);

do while behaves in the same way as while loop the only difference is the conditional expression is checked after executing the loop.

for Loop

for syntax

for(initialization;condition;increment)
{
  statement(s);
}

initialization part takes care of the initial value of a variable or start point of the variable.
conditional part is used to take decision whether the loop will be executed or terminated.
increment part is used to increment or decrement the initialized value of the variable.

Code Example :

package com.fastlearned;

public class LoopExample {
 
 public void forLoop()
 {
  for(int i=10;i<=100;i=i+10)
  {
   System.out.println("inside for Loop "+i);
  }
 }

 public void whileLoop()
 {
  int j = 0;
  while(j<=10)
  {
   System.out.println("inside while Loop "+j);
   j++; 
  }
 }
 
 public void dowhileLoop()
 {
  int z = 0;
  do{
   System.out.println("inside do..while Loop "+z);
   z++;
  }
  while(z<=10);
  
 }
 
 public static void main(String[] args) {
  
  LoopExample loopExample = new LoopExample();
  loopExample.forLoop();
  loopExample.whileLoop();
  loopExample.dowhileLoop();
 }
}

Output :

inside for Loop 10
inside for Loop 20
inside for Loop 30
inside for Loop 40
inside for Loop 50
inside for Loop 60
inside for Loop 70
inside for Loop 80
inside for Loop 90
inside for Loop 100
inside while Loop 0
inside while Loop 1
inside while Loop 2
inside while Loop 3
inside while Loop 4
inside while Loop 5
inside while Loop 6
inside while Loop 7
inside while Loop 8
inside while Loop 9
inside while Loop 10
inside do..while Loop 0
inside do..while Loop 1
inside do..while Loop 2
inside do..while Loop 3
inside do..while Loop 4
inside do..while Loop 5
inside do..while Loop 6
inside do..while Loop 7
inside do..while Loop 8
inside do..while Loop 9
inside do..while Loop 10