Built-in Helpers
In the last section you learned how to write a helper. A helper is usually a simple function that can be used in any template. Ember comes with a few helpers that can make developing your templates a bit easier. These helpers can allow you to be more dynamic in passing data to another helper or component.
Using a helper to get a property dynamically
The {{get}} helper makes it easy to dynamically send the value of a
variable to another helper or component.
This can be useful if you want
to output one of several values based on the result of a computed property.
{{get address part}}if the part computed property returns "zip", this will display the result of
this.get('address.zip'). If it returns "city", you get this.get('address.city').
Nesting built-in helpers
In the last section it was discussed that helpers can be nested.
This can be combined with these sorts of dynamic helpers.
For example, the {{concat}} helper makes it easy to dynamically send
a number of parameters to a component or helper as a single parameter in the
format of a concatenated string.
{{get "foo" (concat "item" index)}}This will display the result of this.get('foo.item1') when index is 1,
and this.get('foo.item2') when index is 2, etc.