Comparing arrays in js

Because their string representations are compared:

 console.log( [2, 6, 10].toString(), [2, 10, 0].toString(), [2, 6, 10] > [2, 10, 0] ); 

Why then is [1,1,1] not identical and not equal to [1,1,1] ?

Why not equal? Equal to:

 var a = [1,1,1]; var b = [1,1,1]; console.log(!(a > b) && !(a < b)); 

And how to compare them then?

Elementally.

When comparing to> and <objects are reduced to primitives - in the case of arrays, these are strings, in which all elements of the array are listed separated by commas. Therefore, [2,6,10]>[2,10,0] is the same as "2,6,10">"2,10,0" , and the lines are compared lexicographically. The first 2 characters are 2, are the same here, but then 6 and 1 are compared further - it is obvious that the first one is larger - that’s true.

If you want to compare arrays element by element, you need to write your own function that compares them in a loop.

PS: A little off topic, but can be useful .

This function will return the number (starting from 1) of the larger array and 0 if they are equal

 function compareArrays(m1, m2) { for(let i=0; i<m1.length && i<m2.length; i++) { if(m1[i]>m2[i]){ return 1; } if(m1[i]<m2[i]){ return 2; } } if(m1.length>m2.length){return 1;} if(m1.length<m2.length){return 2;} if(m1.length==m2.length){return 0;} return false; } console.log(compareArrays([5,6,4], [5,10,0]));