Merge 2-dimensional array into a 1-dimensional array

Question

What is the best way to merge a 2-dimensional array into a 1-dimensional array?

Source Array:

    $example = array(
        array(
            'red',
            'green'
        ),
        array(
            'blue',
            'brown'
        ),
        array(
            'yellow'
        )
    );

Required Output Array:

    $output = array(
        'red',
        'green',
        'blue',
        'brown',
        'yellow'
    );

Solution that works but I am not sure if it is the most efficient because the use of array_merge in a loop seems to be ugly:

    $output = array();
    foreach($example as $v) {
        array_merge($output , $v);
    }

Is there more efficient way of doing this?

There's a method for that in util.php - http://brandonwamboldt.github.io/utilphp/#array_flatten — Bananaapple, Aug 31 '17 at 08:15
Uuups. So long here and produced a doublicate! Shame on me. Sorry for doing that. — steven, Aug 31 '17 at 08:22

score 3 · Answer 1 · answered Aug 31 '17 at 08:15

3

One liner here is:

$output = call_user_func_array('array_merge', $example);

answered Aug 31 '17 at 08:15

u_mulder

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I'd add a comment to describe what this call does ... I'm bound to forget in 6 months time - something like `// flatten array` would save me puzzling later – Wee Zel Aug 31 '17 at 08:25

Abdulla Nilam · Answer 2 · 2017-08-31T09:37:06.123

2

try this

$result = call_user_func_array('array_merge', $example);
print_r($result);

output will be

Edit As a text output

Array ( [0] => red [1] => green [2] => blue [3] => brown [4] => yellow )

Merge 2-dimensional array into a 1-dimensional array

2 Answers2