What are the ways to implement multi-dimensional array sorting algorithm in PHP

This time I will bring you PHP implementationMultidimensional arrayWhat are the ways to sort the algorithm? PHP implements multidimensionalArray sortingWhat are thenotesof the algorithm? What are the following? This is a practical case, let’s take a look at it.

Suddenly remembered an interview question, sorting a multi-dimensional array.

Example:

940, 'key2'=>'blah'), array('key1'=>23, 'key2'=>'this'), array('key1'=>894, 'key2'=>'that') ); //那么怎么对key1或者key2进行排序呢,这里就需要使用到usort($arr, 'myfunction')函数了，它的作用是对$arr使用我们自定义的方法进行排序，具体使用方法可以查看手册 //1.对key1的值进行排序 function asc_key1_sort($x, $y) { //可以输出一下看看是怎么比较的 echo 'Iteration:'.$x['key1'].' vs '.$y['key1']; if($x['key1'] > $y['key1']) { echo 'true
'; return true; }elseif($x['key1'] < $y['key1']) { echo 'false
'; return false; }else { echo '0'; return 0; } } //进行排序 usort($a, 'asc_key1_sort'); var_dump($a); //2.对key2字符进行排序 function asc_key2_sort($x, $y) { //可以使用strcasecmp()函数进行排序 echo 'Iteration:'.$x['key2'].' vs '.$y['key2'].'
'; return strcasecmp($x['key2'], $y['key2']); } //进行排序 usort($a, 'asc_key2_sort'); var_dump($a); ?>

Running result:

Iteration:23 vs 940false Iteration:894 vs 23true Iteration:940 vs 23true Iteration:894 vs 940false array(3) { [0]=> array(2) { ["key1"]=> int(23) ["key2"]=> string(4) "this" } [1]=> array(2) { ["key1"]=> int(894) ["key2"]=> string(4) "that" } [2]=> array(2) { ["key1"]=> int(940) ["key2"]=> string(4) "blah" } } Iteration:that vs this Iteration:blah vs that array(3) { [0]=> array(2) { ["key1"]=> int(940) ["key2"]=> string(4) "blah" } [1]=> array(2) { ["key1"]=> int(894) ["key2"]=> string(4) "that" } [2]=> array(2) { ["key1"]=> int(23) ["key2"]=> string(4) "this" } }

What if my multidimensional array also has key values?

 array('key1'=>940, 'key2'=>'blah'), 349 => array('key1'=>23, 'key2'=>'this'), 43 => array('key1'=>894, 'key2'=>'that') ); //那么怎么对key1或者key2进行排序呢,这里就需要使用到usort($arr, 'myfunction')函数了，它的作用是对$arr使用我们自定义的方法进行排序，具体使用方法可以查看手册 //1.对key1的值进行排序 function asc_key1_sort($x, $y) { //可以输出一下看看是怎么比较的 echo 'Iteration:'.$x['key1'].' vs '.$y['key1']; if($x['key1'] > $y['key1']) { echo 'true
'; return true; }elseif($x['key1'] < $y['key1']) { echo 'false
'; return false; }else { echo '0'; return 0; } } //进行排序 usort($a, 'asc_key1_sort'); var_dump($a); //2.对key2字符进行排序 function asc_key2_sort($x, $y) { //可以使用strcasecmp()函数进行排序 echo 'Iteration:'.$x['key2'].' vs '.$y['key2'].'
'; return strcasecmp($x['key2'], $y['key2']); } //进行排序 usort($a, 'asc_key2_sort'); var_dump($a); ?>

Running results:

Iteration:23 vs 940false Iteration:894 vs 23true Iteration:940 vs 23true Iteration:894 vs 940false array(3) { [0]=> array(2) { ["key1"]=> int(23) ["key2"]=> string(4) "this" } [1]=> array(2) { ["key1"]=> int(894) ["key2"]=> string(4) "that" } [2]=> array(2) { ["key1"]=> int(940) ["key2"]=> string(4) "blah" } } Iteration:that vs this Iteration:blah vs that array(3) { [0]=> array(2) { ["key1"]=> int(940) ["key2"]=> string(4) "blah" } [1]=> array(2) { ["key1"]=> int(894) ["key2"]=> string(4) "that" } [2]=> array(2) { ["key1"]=> int(23) ["key2"]=> string(4) "this" } }

Such a sorting result will not retain 123, 349, and 43. At this time, just replaceusort()withuasort!

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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