How to use strlen function in c language

The strlen function is used to determine the length of a given string. The method of use is as follows: include the string.h header file and declare a constant character pointer pointing to the given string. Call the strlen function, passing the character pointer as a parameter. The return value is stored in a variable of type size_t

How to use the strlen function in C language

strlen function Used to determine the length of a given string, it belongs to the string.h header file in the C standard library.

Syntax:

<code class="c">size_t strlen(const char *str);</code>

Parameters:

• str: To determine the length C string (const pointer).

Return value:

strlen function returns the number of characters contained in str (excluding the null character '\0').

Instructions:

To use the strlen function just follow these steps:

1. Include the string.h header file in your code .
2. Declare a constant character pointer pointing to the given string.
3. Call the strlen function, passing the character pointer as a parameter.
4. Store the return value of the function in a variable of size_t type.

Example:

<code class="c">#include <stdio.h>
#include <string.h>

int main() {
    char str[] = "Hello, world!";
    size_t length = strlen(str);

    printf("String length: %zu\n", length);

    return 0;
}</code>

The above code will print the following output:

<code>String length: 13</code>

The above is the detailed content of How to use strlen function in c language. For more information, please follow other related articles on the PHP Chinese website!