How to use do while in c language

Usage of do while loop in C language: execute the loop body at least once, and then continue execution when the conditional expression is checked to be true. Terminates the loop when the conditional expression is false. Unlike a while loop, the conditional expression is executed once even if it is false.

Usage of do while loop in C language

Introduction:
The do while loop is a statement that implements a loop structure in C language. It executes the loop body at least once before executing the conditional statement.

Syntax:

<code>do {
  // 循环体语句
} while (条件表达式);</code>

Working principle:

1. First execute the statements in the loop body.
2. Then check the conditional expression.
3. If the conditional expression is true, repeat steps 1 and 2.
4. The loop terminates when the conditional expression is false.

Features:

• Unlike the while loop, the do while loop executes the loop body at least once, even if the conditional expression is false at the beginning of the loop .
• If the conditional expression is always true, the do while loop will execute infinite times.

Example:

<code class="c">int main() {
  int num = 10;

  do {
    printf("Num: %d\n", num);
    num--;
  } while (num >= 0);

  return 0;
}</code>

Output:

<code>Num: 10
Num: 9
Num: 8
Num: 7
Num: 6
Num: 5
Num: 4
Num: 3
Num: 2
Num: 1
Num: 0</code>

Notes:

• Conditional expressions must always be of type Boolean (true or false).
• Avoid changing condition variables within the loop body, as this may result in an infinite loop.

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