PHP - 更改字符排序顺序，例如“a”>“{”= True

Question

我试图自定义PHP的usort函数来更改字符排序顺序。

目前，只有“*”符号字符等于小于字母字符的值，例如， “a”，即"*" < "a" = TRUE。其他符号，例如“{”，具有大于字母的值，例如， “a”，即"{" < "a" = FALSE。

我想排序，因此值“{*}”位于排序数组的顶部，就好像值为“*”。这是我目前使用的函数，通过对象的多个属性对对象数组进行排序。 [署名：它的Will Shaver's代码在usort修改版本docs]

function osort($array, $properties) { 
    //Cast to an array and specify ascending order for the sort if the properties aren't already 
    if (!is_array($properties)) $properties = [$properties => true]; 

    //Run the usort, using an anonymous function/closures 
    usort($array, function($a, $b) use ($properties) { 
     //Loop through each specified object property to sort by 
     foreach ($properties as $property => $ascending) { 
      //If they are the same, continue to the next property 
      if ($a -> $property != $b -> $property) { 
       //Ascending order search for match 
       if ($ascending) { 
        //if a's property is greater than b, return 1, otherwise -1 
        return $a -> $property > $b -> $property ? 1 : -1; 
       } 
       //Descending order search for match 
       else { 
        //if b's property is greater than a's, return 1, otherwise -1 
        return $b -> $property > $a -> $property ? 1 : -1; 
       } 
      } 
     } 
     //Default return value (no match found) 
     return -1; 
    }); 

    //Return the sorted array 
    return $array; 
} 

Answer 1

怎么样一个usort是在优先级定义级的一些人物，然后使用常规的strcmp？

事情是这样的：

<?php 

$list = [ 'abc', 
     '{a}', 
     '*', 
     '{*}', 
     '{abc', 
     '}a', 
    ]; // An array of strings to sort 

$customOrderPrioritized = ['{','*','}']; // Add any characters here to prioritize them, in the order they appear in this array 

function ustrcmp($a, $b, $customOrderPrioritized) { 
    if ($a === $b) return -1; // same, doesn't matter who goes first 

    $n = min(strlen($a), strlen($b)); // compare up to the length of the shortest string 
    for ($i = 0; $i < $n; $i++) { 
     if ($a[$i] === $b[$i]) continue; // matching character, continue to compare next 

     $a_prio = in_array($a[$i], $customOrderPrioritized); 
     $b_prio = in_array($b[$i], $customOrderPrioritized); 

     // If either one has a prioritized char... 
     if ($a_prio || $b_prio) { 
      if ($a_prio && $b_prio) { 
       // Both are prioritized, check which one is first... 
       return array_search($a[$i], $customOrderPrioritized) <= array_search($b[$i], $customOrderPrioritized) ? -1 : 1; 
      } elseif ($a_prio) { 
       return -1; // a < b 
      } else { // must be $b_prio 
       return +1; // b > a 
      } 
     } 
     return strcmp($a[i], $b[$i]); // compare single character 
    } 
    // if they have identical beginning, shortest should be first 
    return strlen($a) <= strlen($b) ? -1 : +1; 
} 

usort(
    $list, 
    function($a, $b) use ($customOrderPrioritized){ 
     return ustrcmp($a, $b, $customOrderPrioritized);   
    } 
); // run custom comparison function, pass in $customOrderPrioritized (or make it global) 

print_r($list); // print the list 

/* The sorted array should look like: 
Array 
(
    [0] => {*} 
    [1] => {a} 
    [2] => {abc 
    [3] => * 
    [4] => }a 
    [5] => abc 
) 
*/