Computed is performed immediately after the HTML DOM is loaded, such as assignment; While methods must have certain trigger conditions to execute, such as click events; Watch? It is used to observe data changes on Vue instances. For an object, the key is the observation expression, and the value is the callback. The value can also be a method name or an object containing options. Therefore, their execution sequence is as follows: computed before watch is loaded by default, and methods are not executed. After an event is triggered, methods and then watch.