Why does this map return different results when I apply it on two arrays that are supposed to be perfectly equal to each other?
let a = [1, 2, 3];
a.length = 7;
let b = [1, 2, 3, undefined, undefined, undefined, undefined];
console.log("a: " + a); //a: 1,2,3,,,,
console.log("b: " + b); //b: 1,2,3,,,,
console.log("It is " + a.every((x, i) => x === b[i]) + " that these arrays are perfectly equal."); //It is true that these arrays are perfectly equal.
a = a.map(x => 1);
b = b.map(x => 1);
console.log("a: " + a); //a: 1,1,1,,,,
console.log("b: " + b); //b: 1,1,1,1,1,1,1Array a has 4-7 just as empty. In b 4-7 are undefined. After using the map function, that difference is showing up as "1,1,1,,,," and "1,1,1,1,1,1,1"
