How to use event listening functions in Vue documentation

Vue.js is a popular JavaScript framework that is widely used for building web applications. Vue.js provides a rich API, including how to use event listening functions. In this article, we will explore the use of event listening functions in the Vue documentation.

The event listening function of Vue.js is used to handle user interaction events. Event listener functions in Vue.js are similar to event listener functions in JavaScript, but have different syntax and behavior. The following is the basic syntax of the event listening function:

<v-on:event="method"></v-on:event>

Among them, the v-on instruction is a special instruction provided by Vue.js for binding the event listening function. The event type is specified by the event parameter, which can be any valid DOM event type (such as click, mouseover, etc.). The event handling function is specified through the method parameter, which can be any function in the Vue.js instance. Vue.js will automatically call this function when the event fires.

The following is an example of using the Vue.js event listening function:

<template>
  <div>
    <button v-on:click="sayHello">Click me!</button>
  </div>
</template>

<script>
export default {
  methods: {
    sayHello() {
      alert('Hello, world!')
    }
  }
}
</script>

In this example, we use the v-on:click directive to bindsayHello function to the click event of the "Click me!" button. When the user clicks the button, Vue.js will automatically call the sayHello function and display an alert box with the "Hello, world!" message.

Vue.js event listening function also supports passing parameters. For example, if you want to access the event object in a function, you can use the special $event variable:

<template>
  <div>
    <button v-on:click="handleClick($event)">Click me!</button>
  </div>
</template>

<script>
export default {
  methods: {
    handleClick(event) {
      console.log(event.target.tagName)
    }
  }
}
</script>

In this example, we use the $event variable to The event object is passed to the handleClick function. This function takes the event object as a parameter and prints out the label name of the currently clicked button.

In addition to $event, the Vue.js event listening function also supports passing any number and type of parameters. For example:

<template>
  <div>
    <button v-on:click="handleClick('foo', 123)">Click me!</button>
  </div>
</template>

<script>
export default {
  methods: {
    handleClick(arg1, arg2) {
      console.log(arg1, arg2)
    }
  }
}
</script>

In this example, we passed two extra parameters ('foo' and 123) in the handleClick function. The function takes these two parameters as its arguments and prints them to the console.

In short, the event listening function of Vue.js is a very useful feature that allows you to easily handle user interaction events. You can combine Vue.js event listening functions with other Vue.js features such as computed properties and data binding to create powerful web applications. If you want to learn more about Vue.js, please refer to the Vue.js documentation.

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