How to use strlen function in c++

strlen function is used to calculate the length of a string, excluding the null character at the end of the string. It returns the length of the string as an integer of type size_t, without modifying the original string. Usage: size_t strlen(const char* str);, where str is a constant pointer to a string.

Usage of strlen function in C

Use of strlen function

The strlen function returns the length of the given string, excluding the null character ('\0') at the end of the string.

Function prototype

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

Parameters

• str: Points to the length to be calculated A constant pointer to a string.

Return value

Returns the length of the string (number of bytes), excluding null characters.

Usage

When using the strlen function, you need to pass a constant pointer to a string. Here are some examples:

<code class="cpp">const char* str1 = "Hello";
size_t length1 = strlen(str1); // length1 将为 5

const char* str2 = "";
size_t length2 = strlen(str2); // length2 将为 0</code>

Note

• The string must be null-terminated. The
• strlen function returns an integer of type size_t, which represents the length of the string.
• strlen function does not modify the original string.

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