将array_keys和array_values组合到原始数组中？ [重复]

Question

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• Is elements order the same after array being split by array_keys() and array_values()? [duplicate] 1 answer

I have a method that inserts data into a table using an associative array that looks like this:

array(
    "col1" => "value1",
    "col2" => "value2",
    "col3" => "value3",
);

If I use array_keys() and array_values() on the array passed in can I guarantee that the first item in each set, match the original array passed in?

// Note: validation excluded
$keys   = array_keys($data);   // $data is the array passed in
$values = array_values($data);
$q      = array_pad(array(), count($data), "?");

$this->query("insert into `$this->table` (`" . implode("`,`", $keys) . "`) values (" . implode(",", $q) . ")", $values);

So, with that, can I guarantee that $keys[1] and $values[1] are the same key and value from the original array, or is it possible that they could be col3 and value1?

Another way to say it, if i use array_combine($keys, $values) will I get the original array key => value pair back (item order excluded)?

I am worried that if this doesn't do what I am thinking that value2 may go into col3 instead of col2 or something like that....

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Answer 1

Yes, the functions array_keys($data) and array_values($data) will return the data in the original order.

A search of the PHP reference site for the array_combine() method will show that the method combines the arrays in their original order as well.

For example,

array(
    'red' => 5,
    'green' => 10,
    'blue' => 15
);

would be split into the keys array:

array(
    'red',
    'green',
    'blue'
);

and the values array:

array(
    5,
    10,
    15
);

Combining these arrays with array_combine($keys, $values) would give you the array:

array(
    'red' => 5,
    'green' => 10,
    'blue' => 15
);

Examples from PHP site

Array Keys PHP reference

<?php
    $array = array(0 => 100, "color" => "red");
    print_r(array_keys($array));

    $array = array("color" => array("blue", "red", "green"),
           "size"  => array("small", "medium", "large"));
    print_r(array_keys($array));
?>

The above example will output:

Array
(
    [0] => 0
    [1] => color
)
Array
(
    [0] => color
    [1] => size
)

Array Values PHP reference

<?php
    $array = array("size" => "XL", "color" => "gold");
    print_r(array_values($array));
?>

The above example will output:

Array
(
    [0] => XL
    [1] => gold
)

Array Combine PHP reference

<?php
    $a = array('green', 'red', 'yellow');
    $b = array('avocado', 'apple', 'banana');
    $c = array_combine($a, $b);

    print_r($c);
?>

The above example will output:

Array
(
    [green]  => avocado
    [red]    => apple
    [yellow] => banana
)