JavaScript - merge two arrays of objects and de-duplicate based on property value

Question

I want to update (replace) the objects in my array with the objects in another array. Each object has the same structure. e.g.

var origArr = [
          


        

Answer 1

You could use Array#map in combination with Array#reduce

var origArr = [{ name: 'Trump', isRunning: true }, { name: 'Cruz', isRunning: true }, { name: 'Kasich', isRunning: true }],
    updatingArr = [{ name: 'Cruz', isRunning: false }, { name: 'Kasich', isRunning: false }],
    NEWArr = origArr.map(function (a) {
        return this[a.name] || a;
    }, updatingArr.reduce(function (r, a) {
        r[a.name] = a;
        return r;
    }, Object.create(null)));

document.write('
' + JSON.stringify(NEWArr, 0, 4) + '
');