Strings in C Programming

A string in C is an array of char values terminated by the null character \0. C has no separate built-in string type, so string operations work with character arrays and pointers.

Declare a String Top ↑

char name[] = {'p', 'l', 'u', 's', '2', 'n', 'e', 't', '\0'};
char site[10] = "plus2net";

Array indexes begin at 0. The literal "plus2net" contains 8 visible characters plus the terminating null character, so an array of at least 9 characters is required.

The Null Character Ends the String Top ↑

char name[10] = "plus2net";
name[3] = '\0';
printf("%s\n", name);

Output

plu

Placing \0 at index 3 makes string functions treat that position as the end.

Read Characters Until \0 Top ↑

#include <stdio.h>

int main(void) {
    char name[] = "plus2net";
    int i = 0;

    while (name[i] != '\0') {
        printf("%c ", name[i]);
        i++;
    }

    printf("\nCharacters: %d\n", i);
    return 0;
}

Output

p l u s 2 n e t
Characters: 8

Read a String Safely Top ↑

fgets() is useful when input may contain spaces because it limits the number of characters written to the array.

#include <stdio.h>
#include <string.h>

int main(void) {
    char name[40];

    printf("Enter your name: ");
    if (fgets(name, sizeof name, stdin) == NULL) {
        return 1;
    }

    name[strcspn(name, "\n")] = '\0';

    printf("Welcome %s\n", name);
    return 0;
}

Print a String Vertically and Count the Characters Top ↑

This restores the distinct vertical-printing example from the original pillar page.

#include <stdio.h>

int main(void) {
    char text[] = "Welcome";
    int i = 0;

    for (i = 0; text[i] != '\0'; i++) {
        printf("%c\n", text[i]);
    }

    printf("Total number of chars = %d\n", i);
    return 0;
}

Output

W
e
l
c
o
m
e
Total number of chars = 7

Standard String Length, Copy, Append and Compare Top ↑

Search and Parse Strings Top ↑

Duplicate and Modify Strings Top ↑

Legacy / Non-Standard String Functions Top ↑

Some older compilers provide the following functions. They are not part of older ISO C standards, so each tutorial also shows a portable modern replacement or explains the implementation requirement.

Practice C Strings Top ↑

Related Topic Top ↑

Arrays of strings in C are primarily part of the Array cluster, but they build directly on the character-array concepts covered here.

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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