How can C language determine if a number is an integer?

In C language, you can use the following method to determine if a number is an integer:

1. Use the modulus operator (%) to determine if there is a remainder. If the remainder of a number divided by 1 is 0, then it is an integer.

float num = 10.5;
if(num - (int)num == 0){
    printf("整数\n");
}
else{
    printf("不是整数\n");
}

1. To check for a remainder in C language, you can use the math library function fmod(). This function calculates the remainder when dividing two numbers.

#include <math.h>

float num = 10.5;
if(fmod(num, 1) == 0){
    printf("整数\n");
}
else{
    printf("不是整数\n");
}

1. By converting a floating-point number to an integer using type-casting in the C language, and then comparing it with the original number. If they are equal, it indicates that the original number is an integer.

float num = 10.5;
if((int)num == num){
    printf("整数\n");
}
else{
    printf("不是整数\n");
}

Each of the three methods can be used to determine if a number is an integer, and the specific method chosen depends on personal preference and the specific situation.