C言語のif文｜else if・論理演算子

C言語のif文｜else if・論理演算子 (c言語 if文): practical C programming guide with runnable standard C17 source code that you can edit, compile, and test directly in your browser.

1. C言語のif文｜else if・論理演算子

This guide covers c言語 if文 in standard C (C17) with clear syntax rules and practical compiler patterns. You can run and modify the complete C program below in the online GCC compiler without installing a local IDE.

2. c言語 if文 — Syntax & Best Practices

When working with c言語 if文, always compile with -Wall -Wextra, initialize variables before reading them, and verify input/boundary conditions to prevent undefined behavior.

#include <stdio.h>

int main(void) {
    int score = 85;
    if (score >= 90) {
        printf("Grade A\n");
    } else if (score >= 80) {
        printf("Grade B\n");
    } else {
        printf("Grade C\n");
    }
    return 0;
}