What are Strings?

In C programming, a string is a sequence of characters. Strings are used to store and manipulate text.
Unlike some other programming languages, C doesn't have a built-in string data type. Instead, strings are implemented as arrays of characters.

String Declaration and Initialization

There are several ways to declare and initialize strings in C:

Method 1: Character Array with Size

char name[20];  // Declares a string that can hold up to 19 characters + null terminator

Method 2: Initialize with String Literal

char greeting[] = "Hello World";  // Size automatically determined
char message[50] = "Welcome to C programming";  // Explicit size with initialization

Method 3: Character by Character

char word[6] = {'H', 'e', 'l', 'l', 'o', '\0'};  // Manual initialization

Note: In C, a string is a sequence of characters ending with a null character (\0)

The Null Terminator (\0)

The null terminator is crucial in C strings. It marks the end of the string and helps functions know where to stop processing characters.

char example[] = "Cat";
// Memory layout: ['C']['a']['t']['\0']
// Positions:      [0]  [1]  [2]  [3]

Basic String Operations

Reading Strings

#include <stdio.h>

int main() {
    char name[50];
    
    printf("Enter your name: ");
    scanf("%s", name);  // Note: no '&' needed for strings
    
    printf("Hello, %s!\n", name);
    return 0;
}

Displaying Strings

char city[] = "New York";
printf("City: %s\n", city);  // %s is the format specifier for strings

Important Notes

Aspect	Details
Size Limit	Always ensure your array is large enough to hold the string + null terminator
Input Limitation	scanf("%s", ...) stops at whitespace (space, tab, newline)
Memory	Strings occupy consecutive memory locations
Indexing	Access individual characters using array notation: string[0], string[1], etc.

Common Beginner Mistakes

1. Forgetting the null terminator when manually creating strings
2. Array size too small - remember to account for \0
3. Using & with scanf for strings - not needed since array name is already an address

Strings are fundamental in C programming and you'll use them frequently for handling text data. In the next topics, we'll explore string functions that make working with strings much easier!