C Control Statements

What You’ll Learn

Control statements decide which code runs and when. Without them, every program would execute top to bottom in a straight line. C gives you if for decisions, switch for menu-style choices, and break/continue to steer loops. This hub explains how they fit together and links to 8 full tutorials—each with five examples and FAQs.

Definition and Usage

A control statement alters the default sequential flow of a C program. Selection statements (if, switch) choose which block runs. Jump statements (break, continue, goto) move execution to another point—most often inside loops or switch cases.

Real programs combine these tools: validate input with if-else, route menu numbers with switch, search an array with a for loop and break when found. This page is your map; each tutorial below goes deep on one statement.

📝 Syntax

The main control forms you will use in beginner C programs:

/* if — run when condition is true */
if (condition) {
    /* body */
}

/* if-else — two branches */
if (condition) {
} else {
}

/* else-if ladder — mutually exclusive outcomes */
if (a) {
} else if (b) {
} else {
}

/* switch — compare one value to constants */
switch (value) {
    case 1: /* ... */ break;
    default: break;
}

/* jump inside loops */
break;      /* leave loop or switch */
continue;   /* skip to next iteration */

Choosing the right tool

• Two outcomes — if-else
• Three or more exclusive paths — else-if or switch
• Layered requirements — nested if
• Many constants on one variable — switch
• Stop a loop or skip one pass — break or continue

Compile

gcc main.c -std=c11 -o main

Examples Gallery

Five small programs that combine the most common control statements. Compile with gcc file.c -std=c11 -o out.

#include <stdio.h>

int main(void) {
    int age = 20;

    if (age >= 18) {
        printf("You are eligible to vote.\n");
    }

    return 0;
}

You are eligible to vote.

#include <stdio.h>

int main(void) {
    int n = 7;

    if (n % 2 == 0) {
        printf("%d is even\n", n);
    } else {
        printf("%d is odd\n", n);
    }

    return 0;
}

7 is odd

#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 if (score >= 70) {
        printf("Grade: C\n");
    } else if (score >= 60) {
        printf("Grade: D\n");
    } else {
        printf("Grade: F\n");
    }

    return 0;
}

Grade: B

#include <stdio.h>

int main(void) {
    int choice = 2;

    switch (choice) {
        case 1:
            printf("New file\n");
            break;
        case 2:
            printf("Open file\n");
            break;
        case 3:
            printf("Save file\n");
            break;
        default:
            printf("Unknown option %d\n", choice);
    }

    return 0;
}

Open file

#include <stdio.h>

int main(void) {
    int values[] = {5, -2, 10, 3, 20, 8};
    int n = 6;
    int sum = 0;

    for (int i = 0; i < n; i++) {
        if (values[i] <= 0) {
            continue;
        }
        sum += values[i];
        if (sum > 25) {
            break;
        }
    }

    printf("Stopped at sum: %d\n", sum);

    return 0;
}

Stopped at sum: 28

🚀 Common Use Cases

• Validation — if checks age, password, range.
• Menus — switch on user choice 1–N.
• Classification — else-if for grades, tiers, signs.
• Search — loop with break when item found.
• Filtering — continue to skip bad data rows.
• Games & UI — nested if for state and input.

📝 Notes

• Zero is false in C; any non-zero value is true in conditions.
• Use == to compare, = to assign—do not mix them in if.
• switch only accepts integer types—not float or strings.
• Put break; after switch cases unless fall-through is intentional.
• continue in while may need an early increment to avoid infinite loops.
• Pair this hub with C Loops for full repetition coverage.

🚀 Usage Tips

• Learn in sidebar order — if → if-else → else-if → nested-if → switch → break → continue → goto.
• Brace every branch — prevents dangling else and future bugs.
• Prefer else-if over nested if when outcomes are flat and exclusive.
• Use switch for menus — cleaner than ten else if (x==N) lines.
• Read each tutorial — every statement page has five examples and six FAQs.

💡 Best Practices