Title: Why you should use Object.is() in equality comparison

Author: TarekAlQaddy

Website: https://www.jstips.co/en/javascript/why-you-should-use-Object.is()-in-equality-comparison/

We all know that JavaScript is loosely typed and in some cases it fall behind specially when it comes to equality comparison with ‘==’, comparing with ‘==’ gives unexpected results due to whats called coercion or casting “converting one of the 2 operands to the other’s type then compare”.

我們都知道JavaScript是弱型別語言，在某些情況下，當與“ ==”進行相等性比較時，它特別落后，使用“ ==”進行比較可能會“將2個運算元中的一個強制轉換為另一種型別然后進行比較”而產生意外結果，

1 0 == ' ' //true
2 null == undefined //true
3 [1] == true //true

So they provided us with the triple equal operator ‘===’ which is more strict and does not coerce operands, However comparing with ‘===’ is not the best solution you can get:

因此Javascript提供了三等運算子，三等運算子更加嚴格并且不會將運算元進行強制型別轉換，然而三等運算子也不是最好的解決方案，也存在問題：

1 NaN === NaN //false

The great news that in ES6 there is the new ‘Object.is()’ which is better and more precise it has the same features as ‘===’ and moreover it behaves well in some special cases:

好訊息是，在ES6中有一個新的“ Object.is（）”，它更好，更精確，它具有與“ ===”相同的功能，而且在某些特殊情況下，其表現還不錯：

1 Object.is(0 , ' '); //false
2 Object.is(null, undefined); //false
3 Object.is([1], true); //false
4 Object.is(NaN, NaN); //true

Mozilla team doesn’t think that Object.is is “stricter” than ‘===’ they say that we should think of how this method deal with NaN, -0 and +0 but overall I think it is now a good practice in real applications.

Mozilla團隊不認為"Object.is()"比“ ===”更“嚴格”，應該考慮該方法如何處理NaN，-0和+0，但總的來說，我認為這是一種最佳實踐，

Now this table illustrates..

下表所示：

參考:

Object.is() - JavaScript | MDN

Equality comparisons and sameness

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標籤：JavaScript

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為什么你應該使用 Object.is() 進行相等性比較(譯)

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