isdigit in c

Shell
#include <stdio.h>
#include <ctype.h>

int main()
{
    char c;
    c='0';
    printf("Result when numeric character is passed: %d", isdigit(c));

    c='+';
    printf("\nResult when non-numeric character is passed: %d", isdigit(c));

    return 0;
}
isdigit(myChar);
Source

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