how do i add an item to the end of an array in js code example

Example 1: javascript array add end

// example:
let yourArray = [1, 2, 3];
yourArray.push(4); // yourArray = [1, 2, 3, 4]

// syntax:
// <array-name>.push(<value-to-add>);

Example 2: javascript append array to end of array

const new_array = old_array.concat([value1[, value2[, ...[, valueN]]]])