JS Basics-Common Array manipulation methods

1, Slice ()

Method: Arrayobject.slice (Start,end)
Return value: Returns a new array containing elements from start to end (excluding the element) in the Arrayobject.

2, Splice ()

Method:Array. Splice (index,howmany,item1,.....,ItemX)

index: Where to add/remove elements from

howmany: How many elements should be removed. Must be a number, but it can be "0". If this parameter is not specified, all elements from index start to the end of the original array are deleted.

Item: Optional. The new element to add to the array.

The return value: the Splice () method modifies the array directly, and if the element is removed from the Arrayobject, it is returned as a set of elements containing the deleted element.

3, concat ()

Method: Arrayobject.concat (Arrayx,arrayx,......, Arrayx)
Return value: The method does not alter an existing array, but simply returns a copy of the concatenated array.

4. filter()

方法：arr.filter(callback[, thisArg])


callback: A function used to test each element of an array. Called Using parameters (element, index, array). Returns true to preserve the element (passed test), false is not preserved.

thisArg: Optional. callbackthe value to use when executing this .

The return value, a new array that contains the test pass element. filterdoes not change the original array.

JS Basics-Common Array manipulation methods