text: var app = new Vue ({
  	el: "#app", 
  	data: {
  		msg: "hi, vue",
  	}, 
  
  	//生命周期函数
  	beforeCreate: function() {
  		console.log("beforeCreate")
  	}, 
  	created: function() {
  		console.log("created")
  	}, 
  	beforeMount: function() {
  		console.log("beforeMount")
  	},
  	mounted: function(){
  		console.log("mounted")
  	}, 
  	beforeUpdate: function(){
  		console.log("beforeUpdate")
  	}, 
  	updated: function(){
  		console.log("updated")
  	}
  })
  
  setTimeout(function(){
  	app.msg = "changed......"
  }, 3000)