vue add watcher dynamically code example

Example 1: vue dynamic create watch

vm.$watch('counter', function(newValue, oldValue) {
	alert('Counter changed from ' + oldValue + ' to ' + newValue + '!');
});

Example 2: vue add watcher

vm.$watch('person.name.firstName', function(newValue, oldValue) {
	alert('First name changed from ' + oldValue + ' to ' + newValue + '!');
});