What is flag controlled while loop?

Answer 1

A while loop evaluates a conditional expression at the start of each iteration. If the conditional expression evaluates false, execution passes to the statement that immediately follows the body of the loop. If the conditional expression evaluates true, the body of the loop executes one iteration. When the end of the loop is reached, or a continue statement is encountered within the body of the loop, control passes back to the while statement where the conditional expression is re-evaluated. If a break statement is encountered within the body of the loop, the loop terminates and control passes to the next statement. If a return statement is encountered within the body of the loop, the loop terminates and control passes to the calling function.

while (expression) {

// repeats until the expression evaluates false

}

The braces are optional when the body of the loop is a simple statement. Compound statements must be enclosed in braces.

A flag-controlled while loop has a simple conditional expression that evaluates a Boolean value:

bool x;

// ...

while (x==true) { // flag-controlled loop

// ...

}

}

The above loop can also be written without the equality operator:

while (x) { // flag-controlled loop // ...

}

Moreover, any integral type (such as int or char) will implicitly convert to a bool such that non-zero values evaluate true and zero evaluates false. As such, any integral type can be used in a flag-controlled loop.