String in C

Understanding C Strings

Strings in C are not a distinct data type like in some other programming languages. Instead, they are represented using arrays of characters.

When declaring a string, the null character helps the functions like printf determine where the string ends. This is why strings in C require an additional character to accommodate the null character.

 char str[] = {'H', 'e', 'l', 'l', 'o', '\0'}; 

• Strings in C are not a built-in datatype.
• Strings are character arrays terminated with \0.
• They can be manipulated using standard library functions.

C Programming String Functions Explained

C programming provides a variety of string functions that offer efficient tools to manipulate and handle strings. Understanding these functions is crucial for carrying out common operations such as copying, concatenation, and comparison.

String Manipulation Functions

The C Standard Library provides several functions that you can use to manipulate strings. These functions are available through the string.h header file, which you must include in your program. Below are some of the most common functions:

 #include  char dest[20] = "Hello, "; char src[] = "World!"; strcat(dest, src); // dest now contains "Hello, World!" 

• strlen: Computes the length of a string without counting the null character.
• strcpy: Copies a string from the source to the destination.
• strcat: Appends the source string to the destination string.
• strcmp: Compares two strings lexicographically.

Examples of String Operations in C

In C programming, handling strings requires using various built-in functions. By practicing with examples, you will gain a better understanding of how to perform operations like concatenation, comparison, and copying.

String Concatenation Example

String concatenation in C can be achieved using the strcat function. It appends the source string to the destination string.

 #include   int main() {    char dest[50] = "Hello";    char src[] = " World";    strcat(dest, src);    printf("%s", dest); // Output: Hello World    return 0; } 

String Copying Example

String copying is carried out with the strcpy function. This function transfers characters from the source to the destination.

 #include   int main() {    char destination[20];    char source[] = "Copy This";    strcpy(destination, source);    printf("%s", destination); // Output: Copy This    return 0; } 

String Comparison Example

To compare strings, you can use the strcmp function. It returns zero if the strings are equal, a negative if the first string is less, and a positive if greater than the second string.

 #include   int main() {    char string1[] = "Hello";    char string2[] = "World";    int result = strcmp(string1, string2);    if(result == 0) {        printf("Strings are equal");    } else {        printf("Strings are not equal");    }    return 0; } 

String Manipulation Techniques in C

In C programming, string manipulation involves the use of arrays of characters and various functions to efficiently handle text. Understanding these techniques is essential as it provides the basis for advanced text operations and parsing.

How to Compare String Lengths in C

Comparing string lengths is a common requirement when processing text. In C, this operation can be performed using the strlen function from the string.h library. This function calculates the length of a string by iterating over the character array until it encounters a null character '\0'.

 #include  #include   int main() {    char str1[] = "Hello";    char str2[] = "Goodbye";     int len1 = strlen(str1);    int len2 = strlen(str2);     if(len1 > len2) {        printf("str1 is longer");    } else if(len1 < len2) {        printf("str2 is longer");    } else {        printf("Both strings have the same length");    }     return 0; }