Here is one of the paragraph in YDKJS up and going.
For example, arrays are by default coerced to strings by simply joining all the values with commas (,) in between. You might think that two arrays with the same contents would be == equal, but they’re not:
var a = [1,2,3];
var b = [1,2,3];
var c = "1,2,3";
a == c; // true
b == c; // true
a == b; // false
Why a!=b? I thought a and b have the same elements and they are both array?