C language checks whether the user input is a number

/*
Example: check if input array is a number in C language
*/

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <stdbool.h>

bool isNumber(char number[])
{
    int i = 0;

    // Check whether it is a negative number
    if (number[0] == '-')
        i = 1;
    for (; number[i] != 0; i++)
    {

        if (!isdigit(number[i]))
       //if (number[i] > '9' || number[i] < '0')
            return false;
    }
    return true;
}

int main(int argc, char *argv[]) {
    char num[10];

    scanf(,num);
    if(isNumber(num)){
        printf("Is a number");
    }
    else{
        printf("Is not a number");
    }
    return 0;
}