Often, you can see Array.prototype.slice (arguments, 0); This method can be used in function () {}, which converts the argument list of functions to a true array. Take a look at an example:
Copy Code code as follows:
var slice = Array.prototype.slice;
var toString = Object.prototype.toString;
(function () {
var args = arguments;
Console.log (args, Tostring.call (args)); [1, 2, 3] "[Object Arguments]"
var Argsarr = slice (args, 0);
Console.log (Argsarr, Tostring.call (Argsarr)); [1, 2, 3] "[Object Array]"
} (1,2,3))
We can see the parameter list of the function arguments through the slice call, a second variable array.
Similarly, you can convert a selected DOM element to an array:
Copy Code code as follows:
Slice.call (Document.queryselectorall ("div"));
Let's see if the slide method can convert an object to an array. Take a look at the example:
Copy Code code as follows:
Console.log (Slice.call (' string ')); ["S", "T", "R", "I", "N", "G"]
Console.log (Slice.call) (New string (' string ')); ["S", "T", "R", "I", "N", "G"]
Each time, the string is converted directly into an array.
However, the number, Boolean value, is converted to an empty array:
Copy Code code as follows:
Console.log (Slice.call (33));
Console.log (Slice.call (true));
A normal object is also converted to an empty array unless you add a length attribute to it:
Copy Code code as follows:
Console.log (Slice.call ({name: ' obj '})); // []
Console.log (Slice.call ({0: ' zero ', 1: ' One '}); // []
Console.log ({0: ' zero ', 1: ' One ', Name: ' obj ', length:2}); ["Zero", "one"]
Also, it can be used to clone arrays:
Copy Code code as follows:
var Srcarr = [1,2,3];
var newArr = srcarr.slice (0);
Console.log (Srcarr, NEWARR); [1,2,3] [1,2,3]
Console.log (Srcarr = = NEWARR); False
