Question

For example, I have an array of strings, ['12', '34', '56'], and I want to dynamically update this array by adding additional elements ('78', '90'), or by removing some elements ('34', '56').

Not sure if there’s a better data structure/library that gets the job done. Can someone shed some lights for a JS newbie?

Answer 1

To add to an array use .push.

var arr = ['12', '34', '56'];
arr.push('78', '90');

Removing a specific element, may take a bit more work. To to that, you’ll need to copy the array into a new one (without the element(s) you want to remove).

John Resig (creator of jQuery) posted a function to remove array elements by their indexes (which you’ll need to get 1st). His function is here.

Array.prototype.remove = function(from, to) {
  var rest = this.slice((to || from) + 1 || this.length);
  this.length = from < 0 ? this.length + from : from;
  return this.push.apply(this, rest);
};
var arr = ['12', '34', '56'];
arr.remove(arr.indexOf('34'));
arr.remove(arr.indexOf('56'));

Update: .splice could also work to remove elements.

var arr = ['12', '34', '56'];
arr.splice(arr.indexOf('34'), 1);
arr.splice(arr.indexOf('56'), 1);

Note: Array.indexOf may not work in all browsers. There is a function that will add it to older browsers at the MDN docs page.