Understanding Vue.js v-model Directive with Checkbox Input

In Vue.js, the 'v-model' directive provides us with a simple way to bind data between the model and view layers of the application. When used with a checkbox input, the 'v-model' directive binds to the 'checked' property of the checkbox.

The concept of this binding is that it synchronizes the data of your Vue.js component (model) with the user's input (view). When the checkbox is checked or unchecked by the user, the bound state will automatically update to reflect the current state.

Here's an example:

<template>
  <div>
    <input type="checkbox" id="checkbox" v-model="checked">
    <label for="checkbox">{{ checked }}</label>
  </div>
</template>

<script>
export default {
  data() {
    return {
      checked: false
    }
  }
}
</script>

In this code, 'v-model' directive binds 'checked' data property with the checkbox input. So, when you check or uncheck the checkbox, the value of 'checked' changes correspondingly.

While 'v-model' seems magical, it's important to note that it is simply a syntactic sugar for using v-bind and v-on directives for two-way data binding. Therefore, the above code is equivalent to:

<template>
  <div>
    <input type="checkbox" :checked="checked" @change="checked = $event.target.checked">
    <label for="checkbox">{{ checked }}</label>
  </div>
</template>

Moreover, 'v-model' with a checkbox is useful when you want to bind to an array of selected values through checkbox list. 'v-model' will automatically update the array with checkbox's value when checked and remove it when unchecked.

In conclusion, understanding the usage and mechanism of Vue.js's 'v-model' directive is crucial in creating reactive data bindings. With its help, you can create dynamic Vue applications with intricate data interactions more simply and efficiently. Always remember that it binds to the 'checked' property when working with checkbox inputs.