Comparing two arrays

Question

Why is an array "a" not equal to an array "b"?

https://code.sololearn.com/W5pyBFzbx8AY/?ref=app

Answer 1

In JavaScript, both == and === will not do element-wise checking for arrays. They check if the arrays refer to the same object. Even if the content of two arrays are the same, == will return false since they are different objects.

In terms of "same object", try doing

let a = new Array("a", "b")
let b = a
alert(a == b)

https://stackoverflow.com/questions/7837456/how-to-compare-arrays-in-javascript

Answer 2

Vasiliy At least according to some of the members in SO, it is better to cycle through instead of doing the stringify workaround to do it in one line, due to certain test cases which would fail silently, resulting in nasty bugs.

Answer 3

Blazy You are using JSON.stringify, which would also "work" for new Array(). We were just discussing why JSON.stringify is not a good workaround.

Answer 4

Hatsy Rei thanks for the reply!
So in order to compare two arrays, it is necessary to use the comparison cycle for each value of the array index?

Answer 5

Sure
https://code.sololearn.com/WKJiillNArl0/?ref=app

Answer 6

Blazy
Nice try, but as answered Hatsy Rei we already discussed it ☺
Follow his link, very useful information on this topic.

Answer 7

This is one of the fundamental flaws with js. A variable declared as new Array() is an object and objects cannot be compared, whilst if you declared the array as var a = [ ]; it would have worked to compare them

Answer 8

Blazy
Can you give an example of a code?