isprint() function in C

The isprint() function in C is used to check whether a character is printable or not.

 It belongs to the <ctype.h>  library.

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Steps:

 Checking if a Letter is Ready to Be Printed:

 Imagine you have a letter, say 'A'. isprint() will examine it and say, "Yes, this letter is ready to be printed!"

Inspecting a Whole Sentence:

 If you have a whole sentence, isprint() will go through each character, one by one, and tell you which ones are ready for printing and which ones are not.

Fixing a Broken Sentence:

 Let's say you have a sentence with some strange characters that cannot be printed.

 You can use isprint() to find them and replace them with printable ones, like a detective fixing a broken code.

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Syntax:

int isprint(int c);

Parameters:

c: It's an integer representing a character.

Return Value:

The isprint() function returns an integer value:

Returns a non-zero value if the character c is printable.

Returns 0 otherwise.

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Examples:

1 Check if a Character is Printable:

// program to check if character is printable
#include<stdio.h> 
#include<ctype.h> 

int main() {
    char ch = 'A';
    if (isprint(ch)) {
        printf("%c is printable\n", ch);
    } else {
        printf("%c is not printable\n", ch);
    }
    return 0;
}
	

Output:

A is printable

2 Check if Characters in a String are Printable:

// Program to check if characters in a string are printable
#include<stdio.h> 
#include<ctype.h> 

int main() {
    char str[] = "Hello!\n";
    for (int i = 0; str[i] != '\0'; ++i) {
        if (isprint(str[i])) {
            printf("%c is printable\n", str[i]);
        } else {
            printf("%c is not printable\n", str[i]);
        }
    }
    return 0;
}
	

Output:

H is printable
e is printable
l is printable
l is printable
o is printable
! is printable

3 Convert Non-Printable Characters to Printable Ones:

// program to convert non-printable characters to printable ones.
#include<stdio.h> 
#include<ctype.h> 

int main() {
    char str[] = "Hello!\n";
    for (int i = 0; str[i] != '\0'; ++i) {
        if (!isprint(str[i])) {
            str[i] = '.';
        }
    }
    printf("After converting non-printable characters: %s\n", str);
    return 0;
}
	

Output:

After converting non-printable characters: Hello!.