May 15, 2023 Author - Sai gowtham

How to toggle a class in Vue

vuejs2min read

In this tutorial, we are going to learn about how to dynamically toggle a class in Vue.js with the help of examples.

Toggling the classes

We can toggle a class dynamically in vue by passing an object to the v-bind:class attribute.

In this example, we are toggling a class by clicking the Toggle button.

App.vue

<template>
  <div id="app">
    <div v-bind:class="{box: isActive}"></div>    <button @click="handleToggle">Toggle</button>  </div>
</template>

<script>
export default {
  data() {
    return {
      isActive: true    };
  },
  methods: {
    handleToggle() {
      this.isActive = !this.isActive;    }
  }
};
</script>

In the above code, we have passed {box: isActive} to v-bind:class attribute, where box class will be added to div element if the isActive data property is true; otherwise it is removed.

If you click on a Toggle button the box class is removed, and toggle it again box class is added.

You can also pass multiple classes like this.

App.vue

<template>
  <div id="app">
    <div v-bind:class="{box: isActive, error: isError}"></div>    <button @click="handleToggle">Toggle</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      isActive: true,      isError: false    };
  },
  methods: {
    handleToggle() {
      this.isActive = !this.isActive;
      this.isError = !this.isError;
    }
  }
};
</script>

It will render:

<div class="box"></div>

After clicking the toggle button:

<div class="error"></div>

Using the Array syntax

Similarly, we can also toggle classes by passing an array to the v-bind:class attribute.

App.vue

<template>
  <div id="app">
    <div v-bind:class="[isActive ? box : '' ]"></div>    <button @click="handleToggle">Toggle</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      isActive: true,    };
  },
  methods: {
    handleToggle() {
      this.isActive = !this.isActive;
    }
  }
};
</script>

In the above code, we have used a ternary operator (?) inside the array, where box class is added to div element if an isActive data property is true, otherwise empty string ' ' is added.

You can also pass multiple classes by using an object syntax inside the array syntax.

App.vue

<template>
  <div id="app">
    <div v-bind:class="[{box: isActive}, {error: isError} ]"></div>    <button @click="handleToggle">Toggle</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      isActive: true,      isError: false    };
  },
  methods: {
    handleToggle() {
      this.isActive = !this.isActive;
    }
  }
};
</script>