原文: https://blog.mariusschulz.com/2016/05/25/the-andand-and-operator-in-javascript The && and || Operator in JavaScript ------------------------------------------------- Similar to other C-like programming languages, JavaScript defines the two ope…
What is the !! (not not) operator in JavaScript? 解答1 Coerces强制 oObject to boolean. If it was falsey (e.g. 0, null, undefined, etc.), it will be false, otherwise, true. !oObject //Inverted boolean !!oObject //Non inverted boolean so true boolean repre…
From the JavaScript Reference on MDC, ~ (Bitwise NOT) Performs the NOT operator on each bit. NOT a yields the inverted value (a.k.a. one’s complement) of a. The truth table for the NOT operation is: a NOT a 0 1 1 0 Example: 9 = 0000000000000000000000…
Sometimes we might want to make a function more generic by having it accept a union of different types as an argument. Using the JavaScript “in” operator, we can test for the presence of different properties on the argument object, and TypeScript wil…
Are you baffled(阻碍:使迷惑) by the new operator in JavaScript? Wonder what the difference between a function and a constructor is? Or what the heck a prototype is used for? I’m going to lay it out straight. Now, there’s been a lot of talk for a long time…
原文地址:http://www.2ality.com/2012/09/expressions-vs-statements.html Update 2012-09-21: New in Sect. 4: using void for IIFEs, concatenating IIFEs. This blog post looks at a syntactic distinction that is unfortunately quite important in JavaScript: the d…
javascript prototype原型链的原理 说到prototype,就不得不先说下new的过程. 我们先看看这样一段代码: <script type="text/javascript"> var Person = function () { }; var p = new Person(); </script> 很简单的一段代码,我们来看看这个new究竟做了什么?我们可以把new的过程拆分成以下三步: <1> var p={}; 也就是说,初…
