Why a=[7,9]; b=[7,9] Console.log(a==b)//false ?

Answer 1

JavaScript arrays and objects usually compare by reference. It'll only return true if both variables reference same object.

For example;

a=[7,9]
a=b
console.log(a===b) //true

In this case, both a and b are referencing same array.

Nonetheless, you can still compare two different arrays or objects by value if you iterate through them.