Php 编写了一个函数来缩短数组中的字符串。不'；t在函数完成后更改值

我一直在寻找关于StackOverflow的答案，应用了不同的建议，但没有解决我的问题

我正在尝试编写一个函数，它接受一个数组，并将数组中的每个字符串缩短为3个字符。这是我写的代码：

$days_of_week = array("monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday");

function stringParse(array $string) {
    for($i = 0; $i < count($string); $i++) {
        $string = str_replace($string[$i], substr($string[$i],0,3), $string);
        echo $string[$i].'<br />';
    }
    return $string;
}

stringParse($days_of_week);
foreach($days_of_week as $stry) {echo $stry.'<br />';}

与：

但这也不起作用

我得到的结果是：

mon
tue
wed
thu
fri
sat
sun
monday
tuesday
wednesday
thursday
friday
saturday
sunday

这显然没有改变调用函数后的字符串值。对我做错了什么有什么建议吗

$days_of_week = stringParse($days_of_week);

您需要将返回值赋给变量：-）

此代码适用于我：

<?php
$days_of_week = array("monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday");

function stringParse(array $string) {
    for($i = 0; $i < count($string); $i++) {
        $string = str_replace($string[$i], substr($string[$i],0,3), $string);
        echo $string[$i].'<br />';
    }
    return $string;
}

$days_of_week = stringParse($days_of_week);
foreach($days_of_week as $stry) {echo $stry.'<br />';}

---

您创建的函数返回一个数组，您必须将其分配给变量

$newarray = stringParse($days_of_week);
foreach($newarray as $stry) {echo $stry.'<br />';}

$newarray=stringParse（$days\u/w）；
foreach（$newarray作为$stry）{echo$stry.
；}
试试：

就这样！我没有意识到这一点。我会在7分钟内把你的答案标记为答案。
<?php
$days_of_week = array("monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday");

function stringParse(array $string) {
    for($i = 0; $i < count($string); $i++) {
        $string = str_replace($string[$i], substr($string[$i],0,3), $string);
        echo $string[$i].'<br />';
    }
    return $string;
}

$days_of_week = stringParse($days_of_week);
foreach($days_of_week as $stry) {echo $stry.'<br />';}

$newarray = stringParse($days_of_week);
foreach($newarray as $stry) {echo $stry.'<br />';}

$days_of_week = array("monday", "tuesday", "wednesday", "thursday", "friday", "saturday", "sunday");

$short_days_of_week = array_map(function($value) { return substr($value, 0, 3); }, $days_of_week);

var_dump($short_days_of_week);