Hướng dẫn array_is_list php

[PHP 8 >= 8.1.0]

array_is_list — Checks whether a given array is a list

Description

array_is_list[array $array]: bool

Parameters

The array being evaluated.

Return Values

Returns true if array is a list, false otherwise.

Examples

Example #1 array_is_list[] example

Notes

Note:

This function returns true on empty arrays.

phpnet at jesseschalken dot com ¶

8 months ago

Polyfills that call `array_keys[]`, `array_values[]` or `range[]` are inefficient because they create new arrays unnecessarily.

Please use this polyfill instead which creates no new arrays and only does a single pass over the given array.

divinity76+spam at gmail dot com ¶

4 months ago

slightly optimized version of phpnet at jesseschalken dot com's excellent array_is_list:



benchmarks: //3v4l.org/9BPqL

why is this faster you ask? because post-increment does more,

here is what pre-increment actually means:
step 1: increment the value by 1.
step 2: return the value.

here is what post-increment actually means:
step 1: create a copy of the original value.
step 2: increment the original value by 1.
step 3: return the copy.

another question might be "why didn't you write `if [$k !== ++$i] {` ?  ... that is a good question! turns out that ++$i;if[$k!==$i]{...} is faster on PHP7 than if[$k !== ++$i]{...} for reasons unknown to me.. [if you have an answer, feel free to email me about it!]

[i have NOT checked if PHP8/jit auto-optimize this stuff, but at least back in PHP7 it's true that pre-increment is faster than post-increment, and this polyfill is primarily for PHP7]

Matteo Galletti ¶

10 months ago

Polyfill implementation for PHP versions lower than 8.1.

info at ensostudio dot ru ¶

10 months ago

old school polyfill [:


iradu at unix-world dot org ¶

7 months ago

// How about: