strlen() function in c
The strlen() function in C calculates the length of a given string. The strlen() function is defined in string.h header file. It doesn’t count the null character ‘\0’.
Syntax of C strlen()
The syntax of strlen() function in C is as follows:
size_t strlen(const char* str);
Parameters
The strlen() function only takes a single parameter.
- str: It represents the string variable whose length we have to find.
Return Value
- This function returns the integral length of the string passed.
Example of C strlen()
The below programs illustrate the strlen() function in C:
C
// c program to demonstrate // example of strlen() function. #include <stdio.h> #include <string.h> int main() { // defining string char str[] = "w3wiki" ; // getting length of str using strlen() int length = strlen (str); printf ( "Length of string is : %d" , length); return 0; } |
Output
Length of string is : 13
Important Points about strlen()
The following points should be kept in mind while using strlen():
- strlen() does not count the NULL character ‘\0’.
- The time complexity of strlen() is O(n), where n is the number of characters in the string.
- Its return type is size_t ( which is generally unsigned int ).
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