Why in the following AngularJS example ng-model directive is used? It works without this directive – as one can test it by removing the ng-model directive and setting myCol variable to any valid background color value. What is the use of ng-model directive here?
<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.9/angular.min.js"></script>
<body>
<p>Change the value of the input field:</p>
<div ng-app="" ng-init="myCol='lightblue'">
<input style="background-color:{{myCol}}" ng-model="myCol">
</div>
<p>AngularJS resolves the expression and returns the result.</p>
<p>The background color of the input box will be whatever you write in the input field.</p>
</body>
</html>
Answer
ng-model provides two-way binding, so although ng-init sets the initial value, if you want to be able to dynamically respond to user input (changing the colour via the input) then you need ng-model.