Loops

While loop

while (expr) {
    statements;
}

• Braces are optional (for a single statement).

Do ... while

do {
    statements;
} while (expr);

• Braces are optional (for a single statement).

For loop

for (initial-expr; cond-expr; incr-expr) {
    statements;
}

• initial-expr : Evaluated once before the loop is executed.
• cond-expr : Evaluated before each iteration of the loop; if the value is false, the execution of the loop stops immediately.
• loop-expr : Evaluated at the end of each iteration of the loop, or after a "continue" statement is encountered.

• Braces are optional (for a single statement).

Jump statements

• break : Break from the loop immediately.
• continue : Continue on to the next iteration of the loop.
• goto <label>: Jump to the specified label.

• "goto" statements are sometimes used to break out of nested loops.
• Avoid using "goto" statements whenever possible as they generally cause the code to be less readable and maintainable.

Examples

int sum = 0;
int i = 1;
while (i < 10) {
    if (i == 3) {
        continue;  /* Skip the rest of this loop iteration. */
    }
    sum += i;

    if (sum > 15) {
        break;  /* Exit the loop. */
    }
}

goto LABEL1;
LABEL2:
goto LABEL3;
LABEL1:
goto LABEL2;
LABEL3: