Java While Loops Explained with Examples

While Loop

The while loop repeatedly executes the block of statements until the condition specified within the parentheses evaluates to false . It is usually used when the number of iterations is not fixed.

For instance:

while (some_condition_is_true)
    // do something

Each ‘iteration’ (of executing the block of statements) is preceeded by the evaluation of the condition specified within the parentheses - The statements are executed only if the condition evaluates to true . If it evaluates to false , the execution of the program resumes from the the statement just after the while block.

Note : For the while loop to start executing, you’d require the condition to be true initially. However, to exit the loop, you must do something within the block of statements to eventually reach an iteration when the condition evaluates to false (as done below). Otherwise the loop will execute forever. (In practice, it will run until the JVM runs out of memory.)


In the following example, the expression is given by iter_While < 10 . We increment iter_While by 1 each time the loop is executed. The while loop breaks when iter_While value reaches 10 .

int iter_While = 0;
while (iter_While < 10)
    System.out.print(iter_While + " ");
    // Increment the counter
    // Iterated 10 times, iter_While 0,1,2...9
System.out.println("iter_While Value: " + iter_While);


0 1 2 3 4 5 6 7 8 9
iter_While Value: 10

An infinite while loop is created when the loop remains true infinitely , maybe because there is no change in the change in value of the condition or it never turns false.

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