Usage analysis of in operators in JavaScript

Source: Internet
Author: User

The examples in this article describe the use of the in operator in JavaScript. Share to everyone for your reference. The specific analysis is as follows:

The in operator expects its left operand to be a string or can be converted to a string, hoping that his right operand is an object, and that the expression returns true if the right object has a property name named left operand value:

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1 2 3 4 5 6 7 8 var point = {x:1,y:1}; "X" in point//true "Z",//false "toString" in point//true var ary = [1,2,3]; "0" in ary; True,ary contains index 0 ("0" back conversion to 0); 1 in ary; True,ary contains index 1 3 in ary; False

I hope this article will help you with your JavaScript programming.

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