isprint() in C

The C isprint() function is used to check if a character passed as the argument is a printable character or not. isprint() is defined in the <ctype.h> standard library header file.

Printable characters in C are:

• digits ( 0123456789 )
• uppercase letters ( ABCDEFGHIJKLMNOPQRSTUVWXYZ )
• lowercase letters ( abcdefghijklmnopqrstuvwxyz )
• punctuation characters ( !”#$%&'()*+,-./:;?@[\]^_`{ | }~ )
• space ( )

Note: The isprint() function checks the ASCII value of a character to determine whether it is a printable character or not.

Syntax of isprint()

int isprint (int c);

Parameters

• c: It is the character to be checked.

Return Value

• It returns a non-zero value(true) if the given character is printable.
• If the character is not printable, it returns zero (false).

Complexity Analysis

• Time Complexity: O(1)
• Auxiliary Space: O(1)

Example of isprint()

The below C program calculates the number of printable characters in the string.

Algorithm

1. Traverse the given string character by character up to its length, and check if the character is a printable character using isprint() function.
2. If it is a printable character, increment the counter by 1, else traverse to the next character.
3. Print the value of the counter.

Sample Input : string = ‘My name \n is \n Ayush’
Sample Output : 18

Implementation

Output

My name  is  Ayush
18