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angularjsHow do I use AngularJS to watch for changes in a variable?

AngularJS provides a $watch function that can be used to watch for changes in a variable. To use it, you can inject the $scope service into your controller and then call the $watch function, passing in the variable name you want to watch.

For example, if you want to watch for changes in a variable called name, you can do the following:

$scope.$watch('name', function(newValue, oldValue) {
  console.log('name changed from ' + oldValue + ' to ' + newValue);

The $watch function takes two arguments:

  1. The variable name (in this case name).
  2. A callback function that will be called when the variable changes. This callback function will be passed two arguments: the new value of the variable, and the old value of the variable.

In this example, when name changes, the callback function will log the change to the console.

For more information on the $watch function, see the AngularJS Documentation.

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