Detailed explanation of the usage of substr_count() function in PHP language

PHP is a widely used programming language and is widely used in web development. In these projects, string processing is an important part that cannot be bypassed. In PHP, there are many built-in functions for string processing. For example, functions such as substr_count() can quickly count the number of times a certain substring appears in a given string. In this article, we will introduce the usage of substr_count() function in detail.

1. Syntax

substr_count ( string $haystack , string $needle [, int $offset = 0 [, int $length ]] ) : int

2. Parameters

The substr_count() function has 4 parameters, of which $haystack and $needle are required parameters, and $offset and $length are optional parameters.

• $haystack is the string in which to find the substring;
• $needle is the substring to be found;
• $offset parameter indicates which position Start searching for substrings, which defaults to 0; the
• $length parameter indicates the maximum length of the $haystack string to search for. If not specified, the entire string will be searched by default.

3. Return value

The substr_count() function returns the number of times the specified substring appears in the search range. If the substring is not found, 0 is returned.

4. Examples

Here are a few examples of using the substr_count() function:

// 返回值为 2
echo substr_count("apple orange apple", "apple");

// 返回值为 0
echo substr_count("apple orange apple", "banana");

// 返回值为 1
echo substr_count("apple orange apple", "orange", 6);

// 返回值为 3
echo substr_count("apple orange apple", "a", 0, 10);

5. Instructions

Summary

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