Switch in C

switch is useful when one expression is compared with several fixed values, such as menu choices, day numbers or grade codes. Each case normally ends with break.

Syntax / Basic Pattern

switch(choice) {
case 1: /* code */ break;
case 2: /* code */ break;
default: /* code */
}

Easy points to remember

switch works well with discrete case values.
break prevents execution from falling into the next case.
default runs when no case matches.

⭐ PRACTICE TIP: Type these programs yourself. Change the values and run them again. That is how control statements become easy.

Program 1: Day number

#include <stdio.h>
int main(){ int d=3; switch(d){case 1:printf(“Monday”);break;case 2:printf(“Tuesday”);break;case 3:printf(“Wednesday”);break;default:printf(“Invalid”);} return 0;}

OUTPUT
Wednesday

Program 2: Month number

#include <stdio.h>
int main(){ int m=4; switch(m){case 1:printf(“January”);break;case 4:printf(“April”);break;case 12:printf(“December”);break;default:printf(“Other month”);} return 0;}

OUTPUT
April

Program 3: Menu choice

#include <stdio.h>
int main(){ int c=2; switch(c){case 1:printf(“Add”);break;case 2:printf(“Update”);break;case 3:printf(“Delete”);break;default:printf(“Invalid choice”);} return 0;}

OUTPUT
Update

Program 4: Vowel switch

#include <stdio.h>
int main(){ char c=’o’; switch(c){case ‘a’:case ‘e’:case ‘i’:case ‘o’:case ‘u’:printf(“Vowel”);break;default:printf(“Consonant”);} return 0;}

OUTPUT
Vowel

Program 5: Calculator add

#include <stdio.h>
int main(){ int a=12,b=8; char op=’+’; switch(op){case ‘+’:printf(“%d”,a+b);break;case ‘-‘:printf(“%d”,a-b);break;case ‘*’:printf(“%d”,a*b);break;default:printf(“Invalid”);} return 0;}

OUTPUT
20

Program 6: Grade code

#include <stdio.h>
int main(){ char g=’B’; switch(g){case ‘A’:printf(“Excellent”);break;case ‘B’:printf(“Very good”);break;case ‘C’:printf(“Good”);break;default:printf(“Needs improvement”);} return 0;}

OUTPUT
Very good

Program 7: Traffic signal

#include <stdio.h>
int main(){ char c=’R’; switch(c){case ‘R’:printf(“Stop”);break;case ‘Y’:printf(“Wait”);break;case ‘G’:printf(“Go”);break;default:printf(“Invalid”);} return 0;}

OUTPUT
Stop

Program 8: Season

#include <stdio.h>
int main(){ int m=12; switch(m){case 12:case 1:case 2:printf(“Winter”);break;case 3:case 4:case 5:printf(“Spring”);break;default:printf(“Other season”);} return 0;}

OUTPUT
Winter

Program 9: Days in month

#include <stdio.h>
int main(){ int m=2; switch(m){case 2:printf(“28 or 29 days”);break;case 4:case 6:case 9:case 11:printf(“30 days”);break;default:printf(“31 days”);} return 0;}

OUTPUT
28 or 29 days

Program 10: Food menu

#include <stdio.h>
int main(){ int c=3; switch(c){case 1:printf(“Pizza”);break;case 2:printf(“Burger”);break;case 3:printf(“Pasta”);break;default:printf(“Not available”);} return 0;}

OUTPUT
Pasta

Program 11: Unit choice

#include <stdio.h>
int main(){ int c=1; switch(c){case 1:printf(“Kilometer to meter”);break;case 2:printf(“Meter to centimeter”);break;default:printf(“Invalid”);} return 0;}

OUTPUT
Kilometer to meter

Program 12: Number word

#include <stdio.h>
int main(){ int n=5; switch(n){case 1:printf(“One”);break;case 2:printf(“Two”);break;case 3:printf(“Three”);break;case 4:printf(“Four”);break;case 5:printf(“Five”);break;default:printf(“Other”);} return 0;}

OUTPUT
Five

Program 13: Simple calculator

#include <stdio.h>
int main(){ double a=20,b=4; char op=’/’; switch(op){case ‘+’:printf(“%.0f”,a+b);break;case ‘-‘:printf(“%.0f”,a-b);break;case ‘*’:printf(“%.0f”,a*b);break;case ‘/’:printf(“%.2f”,a/b);break;default:printf(“Invalid”);} return 0;}

OUTPUT
5.00

Program 14: Month quarter

#include <stdio.h>
int main(){ int m=8; switch(m){case 1:case 2:case 3:printf(“Q1”);break;case 4:case 5:case 6:printf(“Q2”);break;case 7:case 8:case 9:printf(“Q3”);break;default:printf(“Q4”);} return 0;}

OUTPUT
Q3

Program 15: Exit menu

#include <stdio.h>
int main(){ int c=4; switch(c){case 1:printf(“Start”);break;case 2:printf(“Settings”);break;case 3:printf(“Help”);break;case 4:printf(“Exit selected”);break;default:printf(“Invalid”);} return 0;}

OUTPUT
Exit selected