C isspace() function

C isspace(int ch)

The isspace() function is used to check whether a character is a space character or not. The function is defined in the ctype.h header file.


int isspace(int argument);

ispunct() Parameters:

Name Description Required /Optional
ch ch is a character of class upper in the current locale. Required

Return value from isupper()

  • The isspace() function return non-zero if ch is a white-space character; otherwise, they shall return 0.

Example: Check white-space character

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

int main()
    char c;
    int result;

    printf("Enter a character: ");
    scanf("%c", &c);
    result = isspace(c);

    if (result == 0)
        printf("Not a white-space character.");
        printf("White-space character.");

    return 0;


Input a character: A
The said character is not a white-space character.
Input a character:
The said character is White-space character.

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C Programming: Tips of the Day

What's an object file in C?

An object file is the real output from the compilation phase. It's mostly machine code, but has info that allows a linker to see what symbols are in it as well as symbols it requires in order to work. (For reference, "symbols" are basically names of global objects, functions, etc.)

A linker takes all these object files and combines them to form one executable (assuming that it can, i.e.: that there aren't any duplicate or undefined symbols). A lot of compilers will do this for you (read: they run the linker on their own) if you don't tell them to "just compile" using command-line options. (-c is a common "just compile; don't link" option.)

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