C Reference Space, formfeed, newline, etc test: isspace()

The isspace() function returns a non-zero if its argument is a single space, newline, tab, form feed, vertical tab, or carriage return.

If the argument is not a single space, newline, tab, form feed, vertical tab, or carriage return , then zero is returned.

isspace() source code example:

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

int main()
{
	int newchar;
	int counter=0;

	char str[]="Testing the isspace function\n";
	while (str[counter])
	{
		newchar=str[counter];
		if (isspace(newchar)) newchar='#';
		putchar (newchar);
		counter++;
	}
	return 0;
}

Note: every space, newline, tab, form feed, vertical tab, or carriage return in the sentence is replaced with a #.