String Comparison function in C Examples

strcmp() Function

The strcmp() function is an in-built function of C programming Which is basically used to compare two strings str1 and str2.

If two strings are same then strcmp() returns 0, otherwise, it returns a non-zero value.

This function compares strings character by character using ASCII value of the characters. The comparison stops when either end of the string is reached or corresponding characters are not same.

C strcmp() syntax

 strcmp(str1, str2);

Example 1: Using strcmp() function


 Enter first string: Welcome
 Enter second string: Prayag

 Entered strings are not same!

 Enter first string: aimtocode
 Enter second string: aimtocode

 You entered the same string two times

Example 2: Without Using strcmp() function


 The strings str1 and str2 are equal

List of String function in C

Functions Description
strcat( ) The strcat() function is used to concatenate one string(source) at the end of another string(destination).
strncat( ) Appends first n characters of a string at the end of another.
strcpy( ) Copies from str2 into str1
strncpy( ) Copies given number of characters of one string to another
strlen( ) Gives the length of str1
strcmp( ) Returns 0 if str1 is same as str2. Returns <0 if strl < str2. Returns >0 if str1 > str2
strcmpi( ) Same as strcmp() function. But, this function negotiates case. “A” and “a” are treated as same.
strchr( ) Returns pointer to first occurrence of char in str1
strrchr( ) last occurrence of given character in a string is found.
strstr( ) Returns pointer to first occurrence of str2 in str1
strrstr( ) Returns pointer to last occurrence of str2 in str1
strdup( ) Duplicates the string
strlwr( ) Converts string to lowercase
strupr( ) Converts string to uppercase
strrev( ) Reverses the given string
strset( ) Sets all character in a string to given character
strnset( ) It sets the portion of characters in a string to given character
strtok( ) Tokenizing given string using delimiter