javascriptjqueryarraysobjectunderscore.js

break array of objects into separate arrays based on a property

Say I have an array like this:

var arr = [
    {type:"orange", title:"First"},
    {type:"orange", title:"Second"},
    {type:"banana", title:"Third"},
    {type:"banana", title:"Fourth"}
];

and I want this to be split up into arrays that have objects which have same type so:

[{type:"orange", title:"First"},
{type:"orange", title:"Second"}]

[{type:"banana", title:"Third"},
{type:"banana", title:"Fourth"}]

But I want to do this generically so not having an if statement that specifies orange or banana

// not like this
for (prop in arr){
    if (arr[prop] === "banana"){
       //add to new array
    }
}

Thoughts? JQuery and Underscore are both options to use.

Solution

  • JQuery and Underscore are both options to use.

    Underscore's groupBy does exactly what you need.

    _.groupBy(arr, "type")