C++ Primer, Fifth Edition

5.4.1. The while Statement

A while statement repeatedly executes a target statement as long as a condition is true. Its syntactic form is

while (condition)      statement

In a while, statement (which is often a block) is executed as long as condition evaluates as true. condition may not be empty. If the first evaluation of condition yields false, statement is not executed.

The condition can be an expression or an initialized variable declaration (§ 5.2, p. 174). Ordinarily, the condition itself or the loop body must do something to change the value of the expression. Otherwise, the loop might never terminate.

Note

Variables defined in a while ...