php - 反转字符串中元音的位置

Question

我想颠倒字符串中元音的顺序。我写了下面的代码，但是结果集是空的。

例子-

“你好”，返回“holle”

“leetcode”，返回“leotcede”

帮我实现这个。

<?php
function reverseVowels($string) {

    $result = '';
    
    $string = array();
    $vowels = array();
    
    $strlength = count($string);
    for ($i=0; $i < $strlength; $i++) {
        $orig = $strlength[$i];
        $char =  strtolower($strlength[$i]);

        if ($char === 'a' || $char === 'e' || $char === 'i' || $char === 'o' || $char === 'u') {
            array_push($vowels, $orig);
            $orig = null; 
        }
        
         array_push($string, $orig);
       
    }
    $new_strlength = count($string);
    
    for ($i=0; $i < $new_strlength; $i++) {
        if (!$string[$i]) {
            $string[$i] = array_splice($vowels, count($vowels) - 1, 1);
        }
    }
    
    $result = $string;
    return $result;
  
}

$res = reverseVowels("hello hello");
print_r($res);

//"hello", return "holle"
//"leetcode", return "leotcede"
?>

Answer 1

我稍微修改了你的:

function reverseVowels($string)
{
    $result = '';
    $out    = [];
    $vowels = [];

    $len = strlen($string);

    for ($i=0; $i < $len; $i++) {
        $orig = $string[$i];
        $char = strtolower($string[$i]);
        if (in_array($char, ['a','e','i','o','u'])) {
            $vowels[] = $orig;
            $orig = null; 
        }
        $out[] = $orig;
    }

    for ($i=0, $j=count($vowels)-1; $i < $len; $i++)
        $result .= $out[$i] == null
            ? $vowels[$j--]
            : $out[$i];

    return $result;
}

或者数组函数:

function reverse_vowels(string $str)
{
    $vowels       = ['a','e','i','o','u'];
    $replacements = [];
    $chars        = str_split($str);
    $replacements = array_intersect($chars, $vowels);
    $replacements = array_combine(
        array_keys($replacements),
        array_reverse($replacements)
    );
    $chars  = array_replace($chars, $replacements);

    return implode('', $chars);
}

echo reverse_vowels('stackoverflow');

输出:

stockevorflaw