copy an array up till certain value code example
Example 1: javascript copy array
var numbers = [1,2,3,4,5];
var newNumbers = Object.assign([], numbers);
Example 2: javascript copy array
// this is for array with complex object
var countries = [
{name: 'USA', population: '300M'},
{name: 'China', population: '1.6B'}
];
var newCountries = JSON.parse(JSON.stringify(countries));