How to retrieve random JSON object by key from JSON dictionary?
iterator, javascript, jquery, json, random
Solution
First, convert the `data` object to an array (the keys on the first level will be lost), like shown here: https://stackoverflow.com/a/11474071/664108
var dataArray = $.map(data, function (value, key) { return value; });
Then shuffle the array (see How to randomize (shuffle) a JavaScript array?)
Alternatively you could just shuffle the keys and then operate on the original object. This way you also have still the keys:
var keyArray = $.map(data, function (value, key) { return key; });
shuffle(keyArray); // example (shuffle function has to be implemented, see above)
for (var i = 0; i < keyArray.length; ++i) {
var current = data[keyArray[i]];
// do stuff with current dataset
}
Addition from the comments
the key array can also be created by:
var keyArray = Object.keys(data);
But note that this only works on modern browsers, you should not use it if you want to support Internet Explorer in versions up to IE 8 (see: http://msdn.microsoft.com/en-us/library/ie/ff688127(v=vs.94).aspx)
Problem
I have a JSON object which consists of a long list of other JSON objects which have some common properties to each other such : ``` var myData = { "0291" : { "Firstname" : "Jeremy", "Surname" : "Dyson" }, "0398" : { "Firstnname" : "Billy", "Surname" : "Bunter" }, "6714" : { "Firstnname" : "Harry", "Surname" : "Peterson" }, "9080" : { "Firstnname" : "Barry", "secondname": "Joe", "Surname" : "Mainwaring"} ... ... } ``` I already built an html template. With the JS, I want to pick or iterate (random pick + loop) through the objects in data{} in random order, so I can fill up the HTML on the fly for each visitor. The random part is important, so each visitor likely get a different data. Plain JavaScript or jQuery solutions will work in the context in which this is being deployed. EDIT: Solution I implemented is below. 1. Collect all keys : ``` var keyArray = Object.keys(myData); ``` 2. Shuffle function: ``` function shuffle(o){ //v1.0 for(var j, x, i = o.length; i; j = parseInt(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x); return o; }; keyArray = shuffle(keyArray); // shuffle it! ``` 3. Loop to iterate: ``` for (var i = 0; i < keyArray.length; ++i) { var current = data[keyArray[i]]; ... // what you want to do each time. } ```