How to Remove Array Element and Then Re-Index Arra

问题:

I have some troubles with an array. I have one array that I want to modify like below. I want to remove element (elements) of it by index and then re-index array. Is it possible?

$foo = array(

    'whatever', // [0]
    'foo', // [1]
    'bar' // [2]

);

$foo2 = array(

    'foo', // [0], before [1]
    'bar' // [1], before [2]

);

回答1:

unset($foo[0]); // remove item at index 0
$foo2 = array_values($foo); // 'reindex' array

回答2:

array_splice($array, 0, 1);

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

回答3:

You better use array_shift(). That will return the first element of the array, remove it from the array and re-index the array. All in one efficient method.

回答4:

array_splice($array, array_search(array_value,$array),1);

回答5:

Unset($array[0]); 

Sort($array); 

---

I don't know why this is being downvoted, but if anyone has bothered to try it, you will notice that it works. Using sort on an array reassigns the keys of the the array. The only drawback is it sorts the values. Since the keys will obviously be reassigned, even with array_values, it does not matter is the values are being sorted or not.

回答6:

Try with:

$foo2 = array_slice($foo, 1);

回答7:

If you use array_merge, this will reindex the keys. The manual states:

Values in the input array with numeric keys will be renumbered with incrementing keys starting from zero in the result array.

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

This is where i found the original answer.

http://board.phpbuilder.com/showthread.php?10299961-Reset-index-on-array-after-unset()

回答8:

In addition to xzyfer's answer

The function

function custom_unset(&$array=array(), $key=0) {
    if(isset($array[$key])){

        // remove item at index
        unset($array[$key]);

        // 'reindex' array
        $array = array_values($array);

        //alternatively
        //$array = array_merge($array); 

    }
    return $array;
}

Use

$my_array=array(
    0=>'test0', 
    1=>'test1', 
    2=>'test2'
);

custom_unset($my_array, 1);

Result

 array(2) {
    [0]=>
    string(5) "test0"
    [1]=>
    string(5) "test2"
  }