Value of the sub pass between components pass parent

 

01 === "parent child transmission using a function of the way to accept 
zi.vue
 <Template> 
    <div> 
        subcomponents:
         <span> hHA </ span> 
        <@ the Click the Button =" clickBtn "> point to my father passed </ button > 
        </ div> 
</ Template> 
Export default { 
    data () { return { 
          MSG: "father to son data transfer" 
        } 
    }, 
    Methods: { 
        clickBtn () { the this $ EMIT ( "GetVal",. the this a .msg) // trigger custom event parameter 1: name of the custom event parameter 2: parameters to be passed         } 
    }, 
} 
fu.vue 
PS =====>

        

           



In all event handlers (whether static or dynamic) are not automatically trigger a custom event to manually trigger on a custom assembly, binding
 <Template> 
    <div> 
       parent component:
        <Child @ GetVal = "getzivalue"> < / Child> 
    </ div> 
</ Template> 


<Script> 
Import from Child "../zi/zi" 
Export default { 
    Components: { 
      Child 
    }, 
    Data () { 
        return { 

        } 
    }, 

    Methods: { 
      getzivalue (Mess) { 
         the console.log ( "parameters passed over son" + Mess) // outputs "father to son data transfer" 
       } 
    } 
}
 </ Script>

 

01 ==== "interview questions

1. v-if和v-show的区别？

v-if使用的是节点操作，removeChild或者appendChild

v-show使用的是css的dispaly来进行隐藏和显示

2. props和data的区别？

data是组件内部数据，由组件自己创建，自己维护

props是外部数据，由外部创建传入，由外部维护！