Example of for (GNU C Language Manual)

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19.6.5 Example of `for`

Here is the for statement from the iterative Fibonacci function:

int i;
for (i = 1; i < n; ++i)
 /* If n is 1 or less, the loop runs zero times, */
 /* since i < n is false the first time. */
 {
 /* Now last is fib (i)
 and prev is fib (i - 1). */
 /* Compute fib (i + 1). */
 int next = prev + last;
 /* Shift the values down. */
 prev = last;
 last = next;
 /* Now last is fib (i + 1)
 and prev is fib (i).
 But that won’t stay true for long,
 because we are about to increment i. */
 }

In this example, start is i = 1, meaning set i to 1. continue-test is i < n, meaning keep repeating the loop as long as i is less than n. advance is i++, meaning increment i by 1. The body is a block that contains a declaration and two statements.