PHP：将循环和变量变量变成一个函数

Question

我怎样才能把下面的代码变成一个函数？

# split the string by string on boundaries formed by the string delimiter will split the value into an array like the example below,
# Array
# (
#     [0] => pg_cat_id=1
#     [1] => tmp_id=4
#     [2] => parent_id=2
# )
$array_parent = explode("&", $string);
//print_r($array_parent);

# now loop the array.
for($i = 0; $i < count($array_parent); $i++)
{   
    # split the array into smaller arrays with the string delimiter, like the example below,
    #   Array
    #   (
    #       [0] => pg_cat_id
    #       [1] => 1
    #   )
    #   Array
    #   (
    #       [0] => tmp_id
    #       [1] => 4
    #   )
    #   Array
    #   (
    #       [0] => parent_id
    #       [1] => 2
    #   )
    $array_child = explode("=", $array_parent[$i]);
    //print_r($array_child);

    # loop each of the array.
    for($a = 0; $a < count($array_child); $a++)
    {   
        # get the first value in each array and store it in a variable.
        $v = $array_child[0];

        # make the variable variable (sometimes it is convenient to be able to have variable variable names. 
        # that is, a variable name which can be set and used dynamically. a variable variable takes the value 
        # of a variable and treats that as the name of a variable). 
        ${$v} = $array_child[1];
    }
}

这样我就可以在需要时调用该函数，如下所示，

$string = 'pg_cat_id=1&tmp_id=4&parent_id=2';

echo stringToVarVars($string);

echo $tmp_id; // I will get 4 as the restult.

非常感谢， 刘

Answer 1

您是否在解析查询字符串？你可以使用parse_str()。

Answer 2

完整的工作代码在这里。无需创建函数。两行代码就够了。

<?php
$string = 'pg_cat_id=1&tmp_id=4&parent_id=2';

parse_str($string, $result);
extract($result);

echo $tmp_id;  // output: 4
?>

Answer 3

使用 global 关键字在函数之外设置变量。

function stringToVarVars($string)
{
    ...
    global ${$v};
    ${$v} = ...;
}

Answer 4

使用数组代替可变变量：

function stringToVarVars($string)
{
    ...
    $result[$v] = ...;
    return $result;
}

$variables = stringToVarVars($string);
echo $variables['tmp_id'];