1. Switch
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
main ()
{
printf("Nisarat Kramsri No.16 M.6/1nn");
Nisarat Kramsri No.16 M.6/1
int choice;
float num1,num2; num1,num2
printf("Please select choicen");
printf("1.Program additionn");
printf("2.Program substractionn");
printf("3.Exit programn");
scanf("%d",&choice);

2. switch(choice) switch
case 3:exit(3);
printf("Enter number1: ");
scanf("%f",&num1);
printf("Enter number2: ");
scanf("%f",&num2);
switch(choice) switch
{
case 1:
printf("%.2f+%.2f=%.2fn",num1,num2,num1+num2);break;
case 2: printf("%.2f-%.2f=%.2fn",num1,num2,num1-
num2);break;
}
getch();

3. }

5. Flowchart
nisarat kramsri
No.16 M.
Choice
yes
Choice=3
no
Choice=1 Choice=2
Num1+num2 Num1-num2