C++ While Loop: Purpose and Usage

In C++, the purpose of a while loop statement is to repeatedly execute a block of code as long as a given condition is true. The while loop checks the condition before each iteration, if the condition is true, it executes the code inside the loop body and then checks the condition again. If the condition is false, the loop ends and the program continues executing the code after the loop.

The general syntax of a while loop is as follows:

while (条件) {
    // 循环体代码
}

A condition is a Boolean expression that, when true, causes the code within the loop body to be repeatedly executed. If the condition is false from the start, the code within the loop body will not be executed.

The main purpose of a while loop is to repeatedly execute a block of code until a certain condition is met, especially when the number of iterations is unknown. It is commonly used in situations where user input or dynamic calculations are involved, or when a specific condition needs to be met before a certain operation can stop.