Difference between v-model and v-bind on Vue.js?

ghz 8months ago ⋅ 146 views

I'm learning Vue with an online course and the instructor gave me an exercise to make an input text with a default value.

I completed it using v-model but, the instructor chose v-bind:value, and I don't understand why.

Can someone give me a simple explanation about the difference between these two and when it's better use each one?

Answers

Both v-model and v-bind:value are Vue.js directives used to bind data to HTML elements, but they serve slightly different purposes.

  1. v-model:

    • v-model is a two-way binding directive, meaning it binds the value of an input element to a data property in your Vue instance and also updates the data property when the input value changes.
    • It's typically used with form elements like <input>, <textarea>, and <select>.
    • v-model is convenient for forms where you want to bind form inputs directly to reactive data properties and automatically update them as the user interacts with the form.

    Example:

    <input type="text" v-model="message">

    In this example, the message data property will be bound to the value of the input element, and any changes made to the input field will automatically update the message data property.

  2. v-bind:value:

    • v-bind:value is a directive used to bind the value of an HTML element to a data property in your Vue instance. However, unlike v-model, it's a one-way binding directive, meaning it only updates the value of the element based on the data property, but it doesn't update the data property when the element's value changes.
    • It's useful when you want to set the initial value of an input element based on some data property, but you don't need two-way binding.

    Example:

    <input type="text" v-bind:value="defaultValue">

    In this example, the initial value of the input element will be set to the value of the defaultValue data property. However, if the user changes the input value, it won't update the defaultValue data property automatically.

In summary, use v-model when you want two-way binding between an input element and a data property, especially in form scenarios. Use v-bind:value when you only need one-way binding to set the initial value of an element based on a data property, but you don't need to update the data property based on user input.

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