watchers in vuejs code example
Example 1: vue watch
var vm = new Vue({
el: '#demo',
data: {
firstName: 'Foo',
lastName: 'Bar',
fullName: 'Foo Bar'
},
watch: {
firstName: function (val) {
this.fullName = val + ' ' + this.lastName
},
lastName: function (val) {
this.fullName = this.firstName + ' ' + val
}
}
})
Example 2: vue add watcher
vm.$watch('person.name.firstName', function(newValue, oldValue) {
alert('First name changed from ' + oldValue + ' to ' + newValue + '!');
});