php代码使用参数化函数反转字符串

Question

Below is my Code to Reverse a String..

The code runs well but I need to wrap this code inside Paramaterized function in which user pass a string inside function and get return output.

<?php
$string = trim("This");
$len =strlen($string);
$stringExp = str_split($string);
for ($i = $len-1; $i >=0;$i--)
{
echo $stringExp[$i];
}
?>

for Ex - I want above string reversal code logic like below function...

<?php
$str = "rahul";
echo reverse($str);

function reverse($str)
{
    for ($i = 0, $j = strlen($str) - 1; $i < $j; $i++, $j--) {
        $tmp = $str[$i];
        $str[$i] = $str[$j];
        $str[$j] = $tmp;
    }

    return $str;
}
?>

Answer 1

Simply try this

$str = "rahul";
echo reverse($str);

function reverse($str)
{
    $tmp = '';
    for($i = (strlen($str)-1);$i >= 0; $i--) {
        $tmp .= $str[$i];
    }

    return $tmp;
}