let vm = new Vue({		
    el:"#app",	
    data:{		
        title:"this is tittle"
    } ,
    methods:{
        foo(){
          alert(this.title);}
    }
});

new Vue({
    el:'#test9',
    data:{
        id1:'HELLO!'
    },
    computed:{
        id:function(){
        return this.id1.split('').reverse().join('')
        }
    }
    
});

// 定义名为 todo-item 的新组件
// Vue.component('todo-item', {
    // template: '<li>这是个待办项</li>'
  // })


var vbm = new Vue({
    el:'#demo',
    data:{
        firstname:'bro',
        lastname:'how'
    },
    computed: {
        fullname: {
          // getter
          get: function () {
            return this.firstname + ' ' + this.lastname
          },
          //setter
          set: function (newValue) {
            var names = newValue.split(' ')
            this.firstname = names[0]
            this.lastname = names[names.length - 1]
          }
         }
      }

});


var watchExampleVM = new Vue({
    el: '#watch-example',
    data: {
      question: '',
      answer: 'I cannot give you an answer until you ask a question!'
    },
    watch: {
      // 如果 `question` 发生改变，这个函数就会运行
      question: function (newQuestion, oldQuestion) {
        this.answer = 'Waiting for you to stop typing...'
        this.debouncedGetAnswer()
      }
    },
    created: function () {
      // `_.debounce` 是一个通过 Lodash 限制操作频率的函数。
      // 在这个例子中，我们希望限制访问 yesno.wtf/api 的频率
      // AJAX 请求直到用户输入完毕才会发出。想要了解更多关于
      // `_.debounce` 函数 (及其近亲 `_.throttle`) 的知识，
      // 请参考：https://lodash.com/docs#debounce
      this.debouncedGetAnswer = _.debounce(this.getAnswer, 500)
    },
    methods: {
      getAnswer: function () {
        if (this.question.indexOf('?') === -1) {
          this.answer = 'Questions usually contain a question mark. ;-)'
          return
        }
        this.answer = 'Thinking...'
        var vm = this
        axios.get('https://yesno.wtf/api')
          .then(function (response) {
            vm.answer = _.capitalize(response.data.answer)
          })
          .catch(function (error) {
            vm.answer = 'Error! Could not reach the API. ' + error
          })
      }
    }
  })