Float and Double Input/Output

#include <stdio.h>
int main()
{
    float num1;
    double num2;

    printf("Enter a number: ");
    scanf("%f", &num1);
    printf("Enter another number: ");
    scanf("%lf", &num2);

    printf("num1 = %f\n", num1);
    printf("num2 = %lf", num2);

    return 0;
}

Output

Enter a number: 12.523
Enter another number: 10.2
num1 = 12.523000
num2 = 10.200000

We use %f and %lf format specifier for float and double respectively.