[javascript] How do I unset an element in an array in javascript?

How do I remove the key 'bar' from an array foo so that 'bar' won't show up in

for(key in foo){alert(key);}

delete foo[key];

:D

If you know the key name simply do like this:

delete array['key_name']

delete foo[key];

:D

This is how I would do it

 myArray.splice( myArray.indexOf('bar') , 1) 

If you know the key name simply do like this:

delete array['key_name']

An important note: JavaScript Arrays are not associative arrays like those you might be used to from PHP. If your "array key" is a string, you're no longer operating on the contents of an array. Your array is an object, and you're using bracket notation to access the member named <key name>. Thus:

var myArray = [];
myArray["bar"] = true;
myArray["foo"] = true;
alert(myArray.length); // returns 0.

because you have not added elements to the array, you have only modified myArray's bar and foo members.

http://www.internetdoc.info/javascript-function/remove-key-from-array.htm

removeKey(arrayName,key);

function removeKey(arrayName,key)
{
 var x;
 var tmpArray = new Array();
 for(x in arrayName)
 {
  if(x!=key) { tmpArray[x] = arrayName[x]; }
 }
 return tmpArray;
}

there is an important difference between delete and splice:

ORIGINAL ARRAY:

[<1 empty item>, 'one',<3 empty items>, 'five', <3 empty items>,'nine']

AFTER SPLICE (array.splice(1,1)):

[ <4 empty items>, 'five', <3 empty items>, 'nine' ]

AFTER DELETE (delete array[1]):

[ <5 empty items>, 'five', <3 empty items>, 'nine' ]

An important note: JavaScript Arrays are not associative arrays like those you might be used to from PHP. If your "array key" is a string, you're no longer operating on the contents of an array. Your array is an object, and you're using bracket notation to access the member named <key name>. Thus:

var myArray = [];
myArray["bar"] = true;
myArray["foo"] = true;
alert(myArray.length); // returns 0.

because you have not added elements to the array, you have only modified myArray's bar and foo members.

delete foo[key];

:D

delete foo[key];

:D