如何更改数组键从 1 而不是 0 开始 [英] how to change the array key to start from 1 instead of 0

问题描述

我在某个数组中有值我想重新索引整个数组，这样第一个值键应该是 1 而不是零，即

I have values in some array I want to re index the whole array such that the the first value key should be 1 instead of zero i.e.

默认情况下，在 PHP 中，数组键从 0 开始.即 0 =>a，1＝＞b，我想重新索引整个数组以从 key = 1 开始，即 1=>a，2＝＞b, ....

By default in PHP the array key starts from 0. i.e. 0 => a, 1=> b, I want to reindex the whole array to start from key = 1 i.e 1=> a, 2=> b, ....

推荐答案

$alphabet = array("a", "b", "c");
array_unshift($alphabet, "phoney");
unset($alphabet[0]);

我决定将此解决方案与本主题中提出的其他解决方案进行基准测试.这是我使用的非常简单的代码:

I decided to benchmark this solution vs. others posed in this topic. Here's the very simple code I used:

$start = microtime(1);
for ($a = 0; $a < 1000; ++$a) {
    $alphabet = array("a", "b", "c");
    array_unshift($alphabet, "phoney");
    unset($alphabet[0]);
}
echo (microtime(1) - $start) . "\n";


$start = microtime(1);
for ($a = 0; $a < 1000; ++$a) {
    $stack = array('a', 'b', 'c');
    $i= 1;
    $stack2 = array();
    foreach($stack as $value){
        $stack2[$i] = $value;
        $i++;
    }
    $stack = $stack2;
}
echo (microtime(1) - $start) . "\n";


$start = microtime(1);
for ($a = 0; $a < 1000; ++$a) {
    $array = array('a','b','c');

    $array = array_combine(
        array_map(function($a){
            return $a + 1;
        }, array_keys($array)),
        array_values($array)
    );
}
echo (microtime(1) - $start) . "\n";

和输出:

0.0018711090087891
0.0021598339080811
0.0075368881225586

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