Type conversion

Learn implicit and explicit (cast) type conversion.

Type conversion means turning a value into another type. There are two kinds:

Explicit conversion, also called a cast, is safer because it states your intent clearly and silences warnings.

Conversion rules

Type conversion in C follows clear rules:

Type matching matters especially in division: 7 / 2 gives 3 (integer division), but 7.0 / 2 gives 3.5 (double division).

Add to the program below a line that casts d to int with (int) d, and a printf call. The output should be 9 9.700000.

Show example solution

#include <stdio.h>

int main(void) {
    double d = 9.7;
    int i = (int) d;
    printf("%d %lf", i, d);
    return 0;
}