PHP – mb_ereg_search_init() function

The mb_ereg_search_init() function in PHP initializes the string and regular expression pattern for multibyte regular expression searches. It prepares the search parameters that will be used by subsequent functions like mb_ereg_search(), mb_ereg_search_pos(), and mb_ereg_search_regs().

Syntax

bool mb_ereg_search_init(
   string $string,
   string $pattern = null,
   string $options = null
)

Parameters

mb_ereg_search_init() accepts three parameters −

• string − The target string to search in.

• pattern − The regular expression pattern (optional).

• options − Search options like "i" for case-insensitive matching (optional).

Return Value

Returns true on success or false on failure.

Example

Here's how to initialize a search for the letter "l" in a UTF-8 encoded string −

<?php
   // Set UTF-8 encoding for regex
   mb_regex_encoding("UTF-8");
   
   // Initialize search for letter "l" in the string
   $result = mb_ereg_search_init("PHP online tutorial", "[l]");
   
   // Check if initialization was successful
   if ($result) {
       echo "Search initialized successfully<br>";
       
       // Now perform the actual search
       if (mb_ereg_search()) {
           echo "Pattern found!";
       }
   } else {
       echo "Failed to initialize search";
   }
?>

Search initialized successfully
Pattern found!

Using with Case-Insensitive Search

You can use the options parameter for case-insensitive matching −

<?php
   mb_regex_encoding("UTF-8");
   
   // Case-insensitive search for "php"
   $result = mb_ereg_search_init("PHP Online Tutorial", "php", "i");
   
   if ($result && mb_ereg_search()) {
       echo "Case-insensitive match found!";
   }
?>

Case-insensitive match found!

Conclusion

The mb_ereg_search_init() function is essential for setting up multibyte regular expression searches in PHP. Always call this function before using other mb_ereg_search_* functions to ensure proper initialization of search parameters.