Array

Test Array

Array.isArray(array)

This does not work to test if its an array.

if (array) {
// empty arrays evaluate as false
}
if (array && array.length > 0) {
// you may still want to capture the array
}

Clone an array

const clone = array.slice(0);

Iterate keys in an array (for...in)

const array = ['x', 'y', 'z'];
for (const key in array) {
console.log(key);
}
0
1
2

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in

Iterate values in an array (for...of)

const array = ['x', 'y', 'z'];
for (const value of array) {
console.log(value);
}
x
y
z

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...of

Appending/merging arrays together

Reuse Array:

array1.push(...array2);

New Array:

const array3 = array1.concat(array2);