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Java while Keyword



The Java while keyword is used to create a conditional statement loop called while loop which executes a set of statements repeatedly until a given condition is true. The While loop can be viewed as a repeating if statement. There are two variants of while loop which is mentioned below:

  • While loop: executes statements after checking the conditions.
  • Do-While loop: executes statements before checking the conditions.

The While Loop

Syntax

while (condition) {
      statements;
    }

Flow Diagram:

Java While Loop

In below mentioned example, program uses while loop to sum all integers from 1 to 5.

public class MyClass {
  public static void main(String[] args) {
    int i = 0;
    int sum = 0;
    while (i <= 5) {
      sum = sum + i;
      i++;
    }
    System.out.println(sum);  
  }
}

The output of the above code will be:

15

The Do-While Loop

The Do-While loop in Java is a variant of while loop which execute statements before checking the conditions. Therefore the Do-While loop executes statements at least once.

Syntax

do {
  statements;
}
while (condition);

Flow Diagram:

Java Do-While Loop

The above explained example is programmed using do-while loop and mentioned below:


public class MyClass {
  public static void main(String[] args) {
    int i = 0;
    int sum = 0;
    
    do{
      sum = sum + i;
      i = i+1;
    }

    while (i <= 5);
    System.out.println(sum);  
  }
}

The output of the above code will be:

15

❮ Java Keywords

5