如何在php中使用“for”循环创建动态递增变量？

Question

如何在php中使用“for”循环创建动态递增变量？ 像明智的一样：$ track_1，$ track_2，$ track_3，$ track_4 .....等......

Answer 1

使用parse_str()或${'track_' . $i} = 'val';。

Answer 2

<?
for($i = 0; $i < 10; $i++) {
  $name = "track_$i";
  $$name = 'hello';
}

print("==" . $track_3);

Answer 3

<?php

for ($i = 1; $i <= 3; $i++) {
    ${"track_{$i}"} = 'this is track ' . $i;  // use double quotes between braces
}

echo $track_1;
echo '<br />';
echo $track_3;

?>

这也适用于嵌套变量：

<?php

class Tracks { 
    public function __construct() {
        $this->track_1 = 'this is friend 1';
        $this->track_2 = 'this is friend 2';
        $this->track_3 = 'this is friend 3';
    }
}

$tracks = new Tracks;

for ($i = 1; $i <= 3; $i++) {
    echo $tracks->{"track_{$i}"};
    echo '<br />';
}

?>