isprint() in C (original) (raw)

Last Updated : 16 Aug, 2024

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

C `

// C program to count printable characters in a string #include <ctype.h> #include <stdio.h> #include <string.h>

// function to calculate printable characters void space(char* str) { int count = 0; int length = strlen(str); for (int i = 0; i < length; i++) { int c = str[i]; // Check if the character is printable if (isprint(c)) { printf("%c", c); count++; } } printf("\n"); printf("%d", count); }

// Driver Code int main() { char str[] = "My name \n is \n Ayush"; space(str); return 0; }

`

Output

My name is Ayush 18