Switch Case

Part of the Fundamentals section of Coddy's C journey — lesson 28 of 63.

The switch statement is a multi-way decision maker that tests whether an expression matches one of several constant integer values, and branches accordingly.

First, define an integer to use with switch:

int day = 3;

Then create a switch statement that evaluates the variable:

switch (day) {
    case 1:
        printf("Monday\n");
        break;
    case 2:
        printf("Tuesday\n");
        break;
    case 3:
        printf("Wednesday\n");
        break;
    default:
        printf("Other day\n");
}

In this example:

Each case represents a possible value of day
When day equals 3, "Wednesday" will be printed

The break statement exits the switch
The default case handles all values not explicitly covered

Without break, execution would "fall through" to the next case.

Challenge

Easy

Write a program that uses a switch statement to convert a numeric grade to a letter grade as follows:

90-100: 'A'
80-89: 'B'
70-79: 'C'
60-69: 'D'
Below 60: 'F'

Your program should read a numeric grade (0-100) and print the corresponding letter grade. Use integer division by 10 to categorize the grades.

If you struggle, follow the example from the lesson

Cheat sheet

The switch statement tests an expression against multiple constant integer values:

int day = 3;
switch (day) {
    case 1:
        printf("Monday\n");
        break;
    case 2:
        printf("Tuesday\n");
        break;
    case 3:
        printf("Wednesday\n");
        break;
    default:
        printf("Other day\n");
}

Each case represents a possible value
The break statement exits the switch
The default case handles unmatched values
Without break, execution falls through to the next case

Try it yourself

#include <stdio.h>

int main() {
    int grade;
    scanf("%d", &grade);
    // Don't change above this line
    
    // Write your code here
    
    return 0;
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Fundamentals

1Introduction

C Language Hello World!Comments Basic Program Structure

4Control Flow

If Statement If - Else Else-IfSwitch CaseTernary Conditional Operator Recap Challenge Nested If - Else

7Functions

Declare a Function Return Types Parameters Recap Challenge #1 Recursion Basics Function Prototypes Recap Challenge #2