PHP RegexIterator::getMode() Method: Usage and Examples

When you need to inspect the matching mode, it helps to understand both the normal result and what changes with different inputs. This guide focuses on practical examples rather than repeating PHP background material.

RegexIterator::getMode provides the behavior described below. RegexIterator operates on another iterator, filtering or transforming its current elements with a PCRE pattern.

What Is RegexIterator::getMode in PHP?

Inspect the matching mode. RegexIterator operates on another iterator, filtering or transforming its current elements with a PCRE pattern.

Its syntax is:

$iterator->getMode(...)

Parameters and return value: Read the argument names and optional values in the signature above. Methods use an existing object, while stand-alone functions take direct arguments. The examples demonstrate the relevant arguments and the value returned or the object modified.

Important: MATCH, GET_MATCH, ALL_MATCHES, SPLIT, and REPLACE produce different iteration values.

Example 1: Basic Usage

This first example demonstrates how to inspect the matching mode with a small input.

<?php

$source = new ArrayIterator(["apple", "pear", "apricot"]);
$iterator = new RegexIterator($source, "/^a/i");
echo $iterator->getMode();

The example uses the simplest useful form. RegexIterator operates on another iterator, filtering or transforming its current elements with a PCRE pattern. The output may depend on the active ICU locale, PHP configuration, or input supplied to the function.

Example 2: Another Case

Here the input or option changes, making it easier to see where the behavior differs. MATCH, GET_MATCH, ALL_MATCHES, SPLIT, and REPLACE produce different iteration values.

<?php

$source = new ArrayIterator(["apple", "pear", "apricot"]);
$iterator = new RegexIterator($source, "/^a/i");
$iterator->setMode(RegexIterator::MATCH);
echo $iterator->getMode();

Compare the result to the first example. Compare RegexIterator modes, preg_match(), and IteratorIterator when a different iteration behavior is needed.

Practical Example: Applying the Function

This standalone example shows how the same operation fits into a small application task.

<?php

$source = new ArrayIterator(["apple", "pear", "apricot"]);
$iterator = new RegexIterator($source, "/^a/i");
$iterator->setMode(RegexIterator::ALL_MATCHES);
var_dump($iterator->getMode() === RegexIterator::ALL_MATCHES);

The example keeps the operation visible and gives you a starting point for using it in an application. MATCH, GET_MATCH, ALL_MATCHES, SPLIT, and REPLACE produce different iteration values.

Important Behavior and Edge Cases

• Core behavior: RegexIterator operates on another iterator, filtering or transforming its current elements with a PCRE pattern.
• Return value: Check the result separately from changes to passed-in arrays, iterators, or object state.
• Data constraints: MATCH, GET_MATCH, ALL_MATCHES, SPLIT, and REPLACE produce different iteration values.
• Environment: Run this example under a PHP version supporting the API; check results and exceptions before using them.

Comparison With Related Functions

Common Beginner Mistakes

Key Takeaways

• RegexIterator::getMode helps you inspect the matching mode.
• RegexIterator operates on another iterator, filtering or transforming its current elements with a PCRE pattern.
• MATCH, GET_MATCH, ALL_MATCHES, SPLIT, and REPLACE produce different iteration values.
• Compare RegexIterator modes, preg_match(), and IteratorIterator when a different iteration behavior is needed.

RegexIterator::getMode is useful when you need to inspect the matching mode. Start with the small examples, then adapt the practical example while respecting its input and environment requirements.