up vote -1 down vote favorite

I have an array as the following:

function example() {
    /* some stuff here that pushes items with
        dynamically created key strings into an array */

    return array( // now lets pretend it returns the created array
        'firstStringName' => $whatEver,
        'secondStringName' => $somethingElse
    );
}

$arr = example();

// now I know that $arr contains $arr['firstStringName'];

I need to find out the index of $arr['firstStringName'] so that I am able to loop through array_keys($arr) and return the key string 'firstStringName' by its index. How can I do that?

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Can you elaborate with a use case of what you're trying to achieve? – nikc.org Jan 4 '12 at 15:34

closed as not a real question by nikc.org, Jakub, Neal, hakre, Gordon Jan 4 '12 at 15:45

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, see the FAQ.

7 Answers

up vote 4 down vote

use array_keys() to get an array of all the unique keys.

Note that an array with named keys like your $arr can also be accessed with numeric indexes, like $arr[0].

http://php.net/manual/en/function.array-keys.php

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up vote 4 down vote 
key($arr);

will return the key value for the current array element

http://uk.php.net/manual/en/function.key.php

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up vote 3 down vote

If the name's dynamic, then you must have something like

$arr[$key]

which'd mean that $key contains the value of the key.

You can use array_keys() to get ALL the keys of an array, e.g.

$arr = array('a' => 'b', 'c' => 'd')
$x = array_keys($arr);

would give you

$x = array(0 => 'a', 1 => 'c');
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up vote 1 down vote

Yes you can infact php is one of the few languages who provide such support..

foreach($arr as $key=>$value)
{

}
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up vote 0 down vote

If you have a value and want to find the key, use array_search() php.net. Use it like this:

$arr = array ('first' => 'a', 'second' => 'b', );
$key = array_search ('a', $arr);

$key will now contain the key for value 'a' (that is 'first').

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up vote 0 down vote

If i understand correctly, can't you simply use:

foreach($arr as $key=>$value){
echo $key;
}

See PHP manual

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You'd just be displaying the array element values, not the array keys.... foreach($arr as $key => $value){ – Mark Baker Jan 4 '12 at 15:39
Edited. Thanks Mark! – Ryan Jan 4 '12 at 15:40
up vote 0 down vote

Check the documentation for array_keys() function

array_keys Function

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