招财象神

書名： Ext JS 3.0 Cookbook
作者名： Jorge Ramon
本章字數： 196字
更新時間： 2021-04-01 13:43:44

Finding objects in an array and removing array items

The main task in this recipe is to find out whether an arbitrary object exists in an array. A way to remove objects from the array is also explored.

How to do it...

The following steps illustrate how you can perform object existence tests and object removal in an array:

Create a sample array as follows:

var colorsArray = new Array();
colorsArray[0] = 'Blue';
colorsArray[1] = 'Red';
colorsArray[2] = 'White';

Determine whether an object exists in an array by trying to find its position in the array:

var position = colorsArray.indexOf('White');
// postition is 2, the index of 'White' in the array.
position = colorsArray.indexOf('Brown');
// 'Brown' does not exist in the array,
// position is -1.

Remove one of the objects from the array:

colorsArray.remove('Blue');
position = colorsArray.indexOf('Blue');
// 'Blue' does not exist anymore,
// position is -1.

How it works...

Ext JS augments the native Array class with Array.indexOf(object) and Array.remove(object). While indexOf(object) works by examining each array element until it finds one that matches the supplied argument, remove(object) uses the native Array.splice(index, howmany, element1,....., elementX) function to remove the supplied argument from the array.

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Ext JS 3.0 Cookbook

Finding objects in an array and removing array items

How to do it...

How it works...