isblank() in C/C++ (original) (raw)

Last Updated : 26 Apr, 2018

The **isblank()**function returns non-zero if ch is a character for which isspace() returns true and is used to separate words. Thus for English, the blank characters are space and horizontal tab.

Header File : ctype.h

Declaration : int isblank(int ch)

difference between isblank() and isspace() The isspace() simply return true if the character is a space. In other words blank character is a space character used to separate words within a line of text and isblank() is used to identify it.isblank() considers blank characters the tab character ('\t') and the space character (' ').isspace() considers space characters : (‘ ‘) – Space, (‘\t’) – Horizontal tab, (‘\n’) – Newline, (‘\v’) – Vertical tab, (‘\f’) – Feed, (‘\r’) – Carriage return Examples:

Input: Geeks for Geeks Output: Geeks for Geeks

Explanation: Since there are 2 spaces for Geeks for Geeks marked by an underscore( _ ) : Geeks_for_Geeks we replace the space with a newline character.

**isblank() C++ Program:**This code prints out the string character by character, replacing any blank character by a newline.

CPP `

// CPP program to demonstrate working // of isblank() #include <ctype.h> #include using namespace std;

int main() { string str = "Geeks for Geeks"; int i = 0;

// to store count of blanks
int count = 0;
while (str[i]) {

    // to get ith character
    // from string
    char ch = str[i++];

    // mark a new line when space
    // or horizontal tab is found
    if (isblank(ch)) {
        cout << endl;
        count++;
    }
    else
        cout << ch;
}

   cout << "\nTotal blanks are : "
        << count << endl;
return 0;

}

`

Output:

Geeks for Geeks Total blanks are : 2