String

String

A string is a sequence of characters stored in contiguous memory locations, terminated by a null character '\0'. Strings in C are represented as arrays of characters (char[]) where each element of the array holds a single character. The null character marks the end of the string.

Here are some key characteristics of strings in C:

1. Null Termination: C strings are null-terminated, meaning that the null character '\0' is used to mark the end of the string. This character is automatically appended to the end of string literals.
2. String Literals: A string literal is a sequence of characters enclosed in double quotes ("). For example, "hello" is a string literal representing the string “hello”. String literals are automatically null-terminated.
3. Character Array: Strings in C are typically represented as arrays of characters (char[]). Each element of the array holds a single character, and the last element is always the null character to signify the end of the string.
4. Character Pointer: Strings can also be represented using pointers to characters (char*). A pointer to the first character of the string is sufficient to access the entire string.
5. Standard Library Functions: C provides a set of standard library functions for working with strings, such as strcpy, strcat, strlen, strcmp, etc. These functions are declared in the string.h header file.

Example :

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

int main() {
    // String declaration and initialization
    char str1[] = "hello";
    char str2[6] = {'h', 'e', 'l', 'l', 'o', '\0'};
    char* str3 = "world";

    // Print strings
    printf("str1: %s\n", str1);
    printf("str2: %s\n", str2);
    printf("str3: %s\n", str3);

    // String length
    printf("Length of str1: %ld\n", strlen(str1));

    // String concatenation
    strcat(str1, " world");
    printf("Concatenated string: %s\n", str1);

    // String comparison
    if (strcmp(str1, str3) == 0) {
        printf("str1 and str3 are equal\n");
    } else {
        printf("str1 and str3 are not equal\n");
    }

    return 0;
}

Output:

str1: hello
str2: hello
str3: world
Length of str1: 5
Concatenated string: hello world
str1 and str3 are equal