Coding Standards: Use array_last() to get the last array element. by Soean · Pull Request #12417 · WordPress/wordpress-develop

Soean · 2026-07-06T12:14:06Z

Replace $array[ count( $array ) - 1 ] constructs with the array_last() function (added in PHP 8.5, polyfilled in compat.php) for improved readability.

Trac ticket: https://core.trac.wordpress.org/ticket/64897

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

Replace `$array[ count( $array ) - 1 ]` constructs with the `array_last()` function (added in PHP 8.5, polyfilled in compat.php) for improved readability.

github-actions · 2026-07-06T12:15:10Z

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github-actions · 2026-07-06T12:29:28Z

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westonruter

Awesome!

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Pull request overview

This PR updates several core code paths to use PHP’s array_last() helper (polyfilled via wp-includes/compat.php) instead of manual count( $array ) - 1 indexing, improving readability and aligning with modern PHP idioms.

Changes:

Replaced manual “last element” indexing with array_last() across multiple files.
Updated trackback parsing, Theme JSON element-path handling, WP_Query author slug parsing, block parser stack access, and Ajax tag search parsing to use array_last().

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Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/wp-trackback.php	Uses `array_last()` when deriving the post ID segment from the request URI.
src/wp-includes/class-wp-theme-json.php	Uses `array_last()` to obtain the current element from metadata paths.
src/wp-includes/class-wp-query.php	Uses `array_last()` for the last author slug segment when parsing nice URLs.
src/wp-includes/class-wp-block-parser.php	Uses `array_last()` to retrieve the current parent from the parsing stack.
src/wp-admin/includes/ajax-actions.php	Uses `array_last()` to grab the final comma-delimited search token.

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+				if ( array_last( $query_vars['author_name'] ) ) {
+					$query_vars['author_name'] = array_last( $query_vars['author_name'] ); // No trailing slash.


westonruter · 2026-07-22T05:04:12Z

Nice thing about this is it is resilient against the possibility of not getting the actual last item in the array if the array is not a list, such as if the integer-indexed array becomes sparse: https://3v4l.org/cMG4N#v8.5.8

Store the result of `array_last()` in a temporary variable instead of calling it twice within the same branch when parsing the author slug from a nice URL. This avoids the repeated (potentially polyfilled) function call and makes the intent clearer.

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Co-authored-by: Weston Ruter <westonruter@gmail.com>

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Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

westonruter · 2026-07-30T19:24:15Z

+		$parent = array_last( $this->stack );
+		if ( ! $parent ) {
+			throw new LogicException( 'The parser stack must not be empty when adding an inner block.' );
+		}


A fatal error would have ensued anyway when attempting to do $parent->block->innerBlocks[] = (array) $block when $parent is null in PHP 8: https://3v4l.org/J1qGg#veol

So this just makes PHP 7 behave consistently with PHP 8.

Nevertheless. There is no @throws tag being added. I guess simpler to just use array_key_last() for now.

See 3dba2c6

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src/wp-includes/class-wp-block-parser.php:348

This refactor introduces a new explicit exception path (throw new LogicException) in add_inner_block(), which changes runtime behavior and goes beyond the PR’s stated “coding standards / readability” scope. It also makes the block parser less “best-effort” (see parse() docblock noting it does not return an error on invalid inputs). Since the previous code already relied on callers ensuring a non-empty stack, consider keeping the change strictly to using array_last() and preserving the prior behavior (letting PHP handle the invariant violation).

		$parent = array_last( $this->stack );
		if ( ! $parent ) {
			throw new LogicException( 'The parser stack must not be empty when adding an inner block.' );
		}

…block(). Replace the `array_last()` call and its accompanying `LogicException` guard with `$this->stack[ array_key_last( $this->stack ) ]`. Both internal call sites are already guarded against an empty stack, so the exception was unreachable from core. Since `add_inner_block()` is a public method of a class that can be replaced via the `block_parser_class` filter, throwing a new exception type would have changed behavior for third-party callers, which is out of scope for a coding standards change. Indexing by `array_key_last()` keeps the readability improvement without introducing a nullable into the expression. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Replace the two remaining `$stack[ count( $stack ) - 1 ]` reads in `Plural_Forms::parse()` with `array_last( $stack )`. Both sites sit inside `while ( ! empty( $stack ) )` loops, so the stack is guaranteed non-empty and the value read is unchanged. `$stack` is only ever appended to with `$stack[] = ...` and shortened with `array_pop()`, so its keys stay sequential and `array_last()` returns the same element as indexing by `count() - 1`. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

…posts(). Read the exploded author name into `$author_name_parts` instead of temporarily storing the array in `$query_vars['author_name']`, so that query var only ever holds a string, and both branches read from the same local. Behavior is unchanged. `$query_vars` is a reference to `$this->query_vars` and feeds `generate_cache_key()`, so the value it ends up with matters: both branches still assign it exactly as before, and only the intervening array assignment -- which every path overwrote two lines later -- is gone. The loose `if ( $last_part )` check is kept deliberately; a strict `'' !== $last_part` would change the result for an author name such as `a/0`. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

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src/wp-includes/class-wp-block-parser.php:345

This line switches to array_key_last() + indexing, but the PR’s stated goal is to replace “get last element” patterns with array_last(). Since array_last() is already polyfilled in wp-includes/compat.php, this can be simplified and made consistent with the rest of the PR by using array_last( $this->stack ) directly.

		$parent                       = $this->stack[ array_key_last( $this->stack ) ];

Coding Standards: Use array_last() to get the last array element.

3a30bd0

Replace `$array[ count( $array ) - 1 ]` constructs with the `array_last()` function (added in PHP 8.5, polyfilled in compat.php) for improved readability.

westonruter approved these changes Jul 20, 2026

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Comment thread src/wp-includes/class-wp-query.php Outdated

Comment on lines +2420 to +2421

if ( array_last( $query_vars['author_name'] ) ) {

$query_vars['author_name'] = array_last( $query_vars['author_name'] ); // No trailing slash.

westonruter reviewed Jul 22, 2026

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Comment thread src/wp-includes/class-wp-block-parser.php Outdated

Copilot AI review requested due to automatic review settings July 22, 2026 06:44

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westonruter reviewed Jul 23, 2026

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Comment thread src/wp-includes/class-wp-block-parser.php Outdated

Update src/wp-includes/class-wp-block-parser.php

a6e6066

Co-authored-by: Weston Ruter <westonruter@gmail.com>

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Merge branch 'trunk' into array_last

38ffbd9

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westonruter and others added 3 commits July 30, 2026 12:50

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		if ( array_last( $query_vars['author_name'] ) ) {
		$query_vars['author_name'] = array_last( $query_vars['author_name'] ); // No trailing slash.

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Soean commented Jul 6, 2026 •

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