Type Casting in C

Type casting means explicitly converting a value from one data type to another. It is useful when you need a particular type for a calculation.

Syntax / Basic Pattern

(target_type) expression

Easy points to remember

(float)a / b can produce decimal division.
Casting does not change the original variable unless you assign the converted value.
Be careful: converting from a larger/decimal type to a smaller/integer type can lose information.

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

Program 1: Integer to float

#include <stdio.h>
int main(){int a=5,b=2;printf(“%.2f”,(float)a/b);return 0;}

OUTPUT
2.50

Program 2: Float to int

#include <stdio.h>
int main(){float x=9.87;int n=(int)x;printf(“%d”,n);return 0;}

OUTPUT
9

Program 3: Char to int

#include <stdio.h>
int main(){char c=’A’;printf(“%d”,(int)c);return 0;}

OUTPUT
65

Program 4: Int to char

#include <stdio.h>
int main(){int n=66;printf(“%c”,(char)n);return 0;}

OUTPUT
B

Program 5: Average

#include <stdio.h>
int main(){int a=70,b=80,c=90;printf(“%.2f”,(float)(a+b+c)/3);return 0;}

OUTPUT
80.00

Program 6: Percentage

#include <stdio.h>
int main(){int obtained=425,total=500;printf(“%.2f%%”,(float)obtained/total*100);return 0;}

OUTPUT
85.00%

Program 7: Division

#include <stdio.h>
int main(){int a=7,b=2;printf(“Int=%d\n”,a/b);printf(“Float=%.2f”,(float)a/b);return 0;}

OUTPUT
Int=3
Float=3.50

Program 8: Double to int

#include <stdio.h>
int main(){double x=12.99;printf(“%d”,(int)x);return 0;}

OUTPUT
12

Program 9: Char code calculation

#include <stdio.h>
int main(){char c=’C’;printf(“%d”,(int)c+1);return 0;}

OUTPUT
68

Program 10: Celsius to Fahrenheit

#include <stdio.h>
int main(){float c=25;printf(“%.1f”,(c*9.0f/5.0f)+32);return 0;}

OUTPUT
77.0

Program 11: Area with double

#include <stdio.h>
int main(){int r=5;double area=3.14159*(double)r*r;printf(“%.2f”,area);return 0;}

OUTPUT
78.54

Program 12: Average with casting

#include <stdio.h>
int main(){int s=251,n=4;printf(“%.2f”,(double)s/n);return 0;}

OUTPUT
62.75

Program 13: Explicit long double

#include <stdio.h>
int main(){int a=100,b=6;printf(“%.3Lf”,(long double)a/b);return 0;}

OUTPUT
16.667

Program 14: Character digit to number

#include <stdio.h>
int main(){char c=’7′;printf(“%d”,(int)c-(int)’0′);return 0;}

OUTPUT
7

Program 15: Mixed calculation

#include <stdio.h>
int main(){int a=3,b=2;double r=(double)(a+b)/b;printf(“%.2f”,r);return 0;}

OUTPUT
2.50