How to use ng-repeat for dictionaries in AngularJs? - angularjs

Question

I know that we can easily use ng-repeat for json objects or arrays like:
<div ng-repeat="user in users"></div>
but how can we use the ng-repeat for dictionaries, for example:
var users = null;
users["182982"] = "{...json-object...}";
users["198784"] = "{...json-object...}";
users["119827"] = "{...json-object...}";
I want to use that with users dictionary:
<div ng-repeat="user in users"></div>
Is it possible?. If yes, how can I do it in AngularJs?
Example for my question:
In C# we define dictionaries like:
Dictionary<key,value> dict = new Dictionary<key,value>();
//and then we can search for values, without knowing the keys
foreach(var val in dict.Values)
{
}
Is there a build-in function that returns the values from a dictionary like in c#?

Answer 1

You can use
<li ng-repeat="(name, age) in items">{{name}}: {{age}}</li>
See ngRepeat documentation. Example: http://jsfiddle.net/WRtqV/1/

Answer 2

I would also like to mention a new functionality of AngularJS ng-repeat, namely, special repeat start and end points. That functionality was added in order to repeat a series of HTML elements instead of just a single parent HTML element.
In order to use repeater start and end points you have to define them by using ng-repeat-start and ng-repeat-end directives respectively.
The ng-repeat-start directive works very similar to ng-repeat directive. The difference is that is will repeat all the HTML elements (including the tag it's defined on) up to the ending HTML tag where ng-repeat-end is placed (including the tag with ng-repeat-end).
Sample code (from a controller):
// ...
$scope.users = {};
$scope.users["182982"] = {name:"John", age: 30};
$scope.users["198784"] = {name:"Antonio", age: 32};
$scope.users["119827"] = {name:"Stephan", age: 18};
// ...
Sample HTML template:
<div ng-repeat-start="(id, user) in users">
==== User details ====
</div>
<div>
<span>{{$index+1}}. </span>
<strong>{{id}} </strong>
<span class="name">{{user.name}} </span>
<span class="age">({{user.age}})</span>
</div>
<div ng-if="!$first">
<img src="/some_image.jpg" alt="some img" title="some img" />
</div>
<div ng-repeat-end>
======================
</div>
Output would look similar to the following (depending on HTML styling):
==== User details ====
1. 119827 Stephan (18)
======================
==== User details ====
2. 182982 John (30)
[sample image goes here]
======================
==== User details ====
3. 198784 Antonio (32)
[sample image goes here]
======================
As you can see, ng-repeat-start repeats all HTML elements (including the element with ng-repeat-start). All ng-repeat special properties (in this case $first and $index) also work as expected.

Answer 3

JavaScript developers tend to refer to the above data-structure as either an object or hash instead of a Dictionary.
Your syntax above is wrong as you are initializing the users object as null. I presume this is a typo, as the code should read:
// Initialize users as a new hash.
var users = {};
users["182982"] = "...";
To retrieve all the values from a hash, you need to iterate over it using a for loop:
function getValues (hash) {
var values = [];
for (var key in hash) {
// Ensure that the `key` is actually a member of the hash and not
// a member of the `prototype`.
// see: http://javascript.crockford.com/code.html#for%20statement
if (hash.hasOwnProperty(key)) {
values.push(key);
}
}
return values;
};
If you plan on doing a lot of work with data-structures in JavaScript then the underscore.js library is definitely worth a look. Underscore comes with a values method which will perform the above task for you:
var values = _.values(users);
I don't use Angular myself, but I'm pretty sure there will be a convenience method build in for iterating over a hash's values (ah, there we go, Artem Andreev provides the answer above :))

Answer 4

In Angular 7, the following simple example would work (assuming dictionary is in a variable called d):
my.component.ts:
keys: string[] = []; // declaration of class member 'keys'
// component code ...
this.keys = Object.keys(d);
my.component.html: (will display list of key:value pairs)
<ul *ngFor="let key of keys">
{{key}}: {{d[key]}}
</ul>