break array of objects into separate arrays based on a property

Question

Say I have an array like this:

var arr = [
    {type:\"orange\", title:\"First\"},
    {type:\"orange\", title:\"Second\"},
    {type:\"banana\", title:\"Thi         


        

Answer 1

This assumes an array of objects:

function groupBy(array, property) {
    var hash = {};
    for (var i = 0; i < array.length; i++) {
        if (!hash[array[i][property]]) hash[array[i][property]] = [];
        hash[array[i][property]].push(array[i]);
    }
    return hash;
}

groupBy(arr,'type')  // Object {orange: Array[2], banana: Array[2]}
groupBy(arr,'title') // Object {First: Array[1], Second: Array[1], Third: Array[1], Fourth: Array[1]}