Shulou(Shulou.com)06/03 Report--

This article will explain in detail how several JavaScript native methods you may not know are. The quality of the article is high, so Xiaobian shares it with you as a reference. I hope you have a certain understanding of relevant knowledge after reading this article.

Since ES6 was released, many new, convenient native methods have been added to JavaScript's new standard. However, I see a lot of old code in the GitHub repository. That doesn't mean they're necessarily bad, but the features I'm going to introduce will help make your code more readable and beautiful.

Number.isNaN vs. isNaN

NaN is a numeric type.

typeof NaN === 'number' // true

Therefore, you cannot distinguish NaN from numbers.

Even Object.prototype.toString.call returns [object Number] for NaN and numbers. You may already know that you can check if the parameter is NaN using the isNaN method. But since ES6, the number constructor has started to take isNaN as its method. What's the difference?

isNaN--checks if the value passed is a number or cannot be converted to a number.

Number.isNaN--Checks if the value passed is not a number.

Here's an example.

Number.isNaN({}); //

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.