Create an array based of another arrays values by defining a key?

I'm trying to create an array based of another arrays values by defining a key?

E.g.

$old_array = array('hey', 'you', 'testing', 'this');

function get_new_array($key) {
global $old_array;

//return new array...
}

$new_array = get_new_arr开发者_开发知识库ay(2); //would return array('hey, 'you', 'testing'); as its the values of all the keys before the key 2 and the 2 key itself

Appreciate all help! :B

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Use array_slice():

function get_new_array($key) {
    global $old_array;
    return array_slice($old_array, 0, $key+1);
}

Some suggestions:

• You wanted to return the sub-array up to and including the key. It's far more common to instead return up to but excluding the key. Hence the +1 was necassary.
• Using $old_array as a global is poor style. I recommend rather passing it as an argument to the function.
• Since array_slice() already does what you want, except for minor differences, I'd call it directly rather than writing a wrapper function which hides functionality.

---

$new=array_slice($old_array,0,3);

---

Use array_slice().

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Use array_slice() function:

$input = array("a", "b", "c", "d", "e");

$output = array_slice($input, 2);      // returns "c", "d", and "e"
$output = array_slice($input, -2, 1);  // returns "d"
$output = array_slice($input, 0, 3);   // returns "a", "b", and "c"

Link to manual.