C Loop Statements

This chapter introduces three types of loops: for, while, do-while, as well as the usage and considerations of break/continue.

1. for Loop

for (int i = 0; i < n; ++i) {
    // ...
}

• Suitable for loops with known iteration count

2. while Loop

while (cond) {
    // ...
}

• Suitable for condition-driven loops

3. do-while Loop

do {
    // ...
} while (cond);

• Executes at least once

4. break and continue

• break: Immediately ends the current loop
• continue: Skips the remaining part of the current iteration and enters the next iteration

5. Multi-level Nesting and Performance

• Try to avoid deep nesting, consider splitting into functions
• Be aware of expensive operations inside loops (like I/O)

6. Example: Finding Maximum Value in Array

#include <stdio.h>

int max(const int *a, int n) {
    if (n <= 0) return 0;
    int m = a[0];
    for (int i = 1; i < n; ++i) if (a[i] > m) m = a[i];
    return m;
}

int main(void) {
    int arr[] = {3, 9, 4, 7};
    printf("%d\n", max(arr, 4));