When working with PHP, you may need to find the next occurrence using stateful multibyte regex search. This guide explains the operation, shows what its arguments mean, and uses three separate examples to make the result easier to understand.
mb_ereg_search: Stateful search functions read text previously assigned with mb_ereg_search_init().
What Is mb_ereg_search in PHP?
Find the next occurrence using stateful multibyte regex search. Stateful search functions read text previously assigned with mb_ereg_search_init().
Syntax:
mb_ereg_search(?string $pattern = null, ?string $options = null): bool
Parameters and return value: The signature above identifies the arguments and return type where the API has a single call. For topic guides, follow the sequence of calls in the examples. Always distinguish a returned value from an object or variable modified by reference.
Important: Initialize the search data before searching. The functions share a search cursor, so reset it before processing another input.
Example 1: Basic Usage
This example introduces the operation with a short and predictable input.
<?php
mb_ereg_search_init("Room 25");
var_dump(mb_ereg_search("[0-9]+"));
The code focuses on the main operation. Stateful search functions read text previously assigned with mb_ereg_search_init().
Example 2: Another Case
Now compare a different input, locale, date, or option to see another part of the behavior.
<?php
mb_ereg_search_init("No digits here");
var_dump(mb_ereg_search("[0-9]+"));
What changes? Initialize the search data before searching. The functions share a search cursor, so reset it before processing another input.
Practical Example: Applying It in an Application
Use the following separate example as a starting point for a small application task. Check any extension or environment requirements below before running it.
<?php
$logLine = "id=14 status=200";
mb_ereg_search_init($logLine);
while (mb_ereg_search("[0-9]+")) {
print_r(mb_ereg_search_getregs());
}
The practical example demonstrates how to apply this operation to multiple values, a reusable task, or a validated input. Stateful search functions read text previously assigned with mb_ereg_search_init().
Important Behavior and Edge Cases
- Core behavior: Stateful search functions read text previously assigned with mb_ereg_search_init().
- Inputs and results: Initialize the search data before searching. The functions share a search cursor, so reset it before processing another input.
- Alternatives: mb_ereg_search_regs() returns captures; preg_match_all() provides stateless PCRE matching.
- Compatibility: mbstring is required for mb_* functions.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
mb_ereg_search | Find the next occurrence using stateful multibyte regex search. |
| Related PHP approach | mb_ereg_search_regs() returns captures; preg_match_all() provides stateless PCRE matching. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Using an incorrect input or option | Initialize the search data before searching. The functions share a search cursor, so reset it before processing another input. |
| Confusing this API with a related operation | mb_ereg_search_regs() returns captures; preg_match_all() provides stateless PCRE matching. |
| Assuming output is identical across environments | Check return values and required extensions or versions. mbstring is required for mb_* functions. |
Key Takeaways
- mb_ereg_search helps you find the next occurrence using stateful multibyte regex search.
- Stateful search functions read text previously assigned with mb_ereg_search_init().
- Initialize the search data before searching. The functions share a search cursor, so reset it before processing another input.
Use mb_ereg_search when you need to find the next occurrence using stateful multibyte regex search. Start with the first example, compare the second, and adapt the practical example to your inputs. Confirm the return value and environment requirements before adding it to production code.