JavaScript's double not operatoris basically double use of (!) operator. This is alogical not operator. (!!) operator converts non-Boolean to Boolean. As you know,!operator reverses the logic, i.e., it returnfalsefor!truevalue andtruefor!false. Examples of (!) Operator !false Output: ...
is not an operator, it's just the!operator twice. Real World Example "Test IE version": let isIE8 = false; isIE8 = !! navigator.userAgent.match(/MSIE 8.0/); console.log(isIE8); // returns true or false 1. 2. 3. If you ⇒ console.log(navigator.userAgent.match(/MSIE 8.0/)...
What is decrement ( ) operator in JavaScript - The decrement operator in Javascript decreases an integer value by one. This operator is often utilized in loops, counters, and mathematical computations where a value has to be decreased sequentially. Types
I've seen some people usingvoidoperator in their code. I have also seen this inhrefattributes:javascript:void(0)which doesn't seem any better thanjavascript:; So, what is the justification of using thevoidoperator? 回答 The JavaScript, thevoidoperator is used to explicitly return undefined. I...
If p is a false value, !p is true, and !!p is false. If p is a true value, !p is false, and !!p is true. Truthy and Falsy Values In JavaScript values are inherentlytruthyorfalsywhen evaluated in a boolean context. The !! operator uses this behavior to convert any value totrue...
While many people are familiar with Java from interactive website features, users may be less familiar with JavaScript — or, indeed, they may wrongly consider the two to be the same. In this article, we discuss what JavaScript is and the differences between Java and JavaScript. Then we’ll...
The implementation of JavaScript code in Node.js also plays an important role in web development. Node.js can reduce server response time due to its single-threaded nature and non-blocking architecture and omit delays.Node.js is also lightweight enough to serve as a scalable tool for ...
So, what is the difference between a normal function and an arrow function? 🤔️ 1. this points to In JavaScript, thethisis a basic and important knowledge point. 1.1 Ordinary functions In ordinary functions,thisis dynamic, and its value depends on how the function is called. There are...
What isnon-null operatorin typescript? What does the ? in the ts type mean? // https://github.com/vuejs/vue/blob/dev/src/core/observer/watcher.js before: ?Function; options?: ?Object, This is a concept in the interface of ts. The interface of ts is "duck typing" or "structural...
The ObjectMaker function was executed, with // obj1 in place of this... so obj.a was set to 'first'. obj.a; // returns 'first' obj.b; // obj doesn't have a property called 'b', so JavaScript checks // its [[prototype]]. Its [[prototype]] is the same as ObjectMaker....