Properties of while loop

In the above example, if the user enters 0, as the value for upper limit. In the while condition we test (number <= upperLimit) i.e. number is less than or equal to upperLimit ( 0 ), this test return false. The control of the program will go to the next statement after the while block. The statements in while structure will not be executed even for a single time. So the property of while loop is that it may execute zero or more time. The while loop is terminated, when the condition is tested as false. Make sure that the loop test has an adequate exit. Always use braces for the loop structure. If you forget to put the braces, only one statement after the while statement is considered in the while block. Infinite Loop: Consider the condition in the while structure that is (number <= upperLimit) and in the while block the value of number is changing (number = number + 1) to ensure that the condition is tested again next time. If it is true, the while block is executed and so on. So in the while block statements, the variable used in condition must change its value so that we have some definite number of repetitions. What will happen if we do not write the statement number = number + 1; in our program? The value of number will not change, so the condition in the while loop will be true always and the loop will be executed forever. Such loops in which the condition is always true are known as infinite loops as there are infinite repetitions in it. For previous lesson click here: sum of even numbers with while
For next lesson click here: While Flow Chart

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Properties of while loop