How to create a computed observable array in Knockout

knockout.js ko.observablearray computed-observable
Matt Mangold picture Matt Mangold · Jul 2, 2012 · Viewed 40.4k times · Source

I would like to know how to create a computed observable array.

In my view model, I have 2 observable arrays, and I would like to have a computed observable array that is simply both arrays combined.

function ViewModel() {
    var self = this;
    self.listA= ko.observableArray([]);
    self.listB = ko.observableArray([]);
    self.masterList= //combine both list A and B

Answer

Brian S picture Brian S · Jul 2, 2012

This will combine the two arrays and return the combined list. However, it is not a computed observable array (don't know if that is even possible), but a regular computed observable. 

self.masterList = ko.computed(function() {
    return this.listA().concat(this.listB());
}, this);

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