Several ways to use v-bind binding with Class and Style in Vue

<div id="app">
    <div class="button-group">
      <button
        v-for="(tab, index) in tabs" 
        v-bind:key="index" 
        v-bind:class="{active: currentTab === tab}" 
        v-on:click="currentTab = tab"
      >{{tab}}</button>
    </div>
    <component v-bind:is="currentTabComponent"></component>
</div>
<script>
Vue.component("tab1", {
    "template": "<p>This is tab 1</p>"
});
Vue.component("tab2", {
  "template": "<p>This is tab 2</p>"
});
Vue.component("tab3", {
  "template": "<p>This is tab 3</p>"
});
var vm = new Vue({
  el: "#app",
  data: {
    currentTab: "tab1",
    tabs: ["tab1", "tab2", "tab3"]
  },
  computed: {
    currentTabComponent() {
      return this.currentTab;
    }
  }
});
</script>

<button 
    class="btn"
    v-bind:class="{'btn-primary': isPrimary, active: isActive}"
></button>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        isPrimary: true,
        isActive: true  
      }
    });
</script>

<button class="btn btn-primary active"></button>

<button class="btn" v-bind:class="activePrimary"></button>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        activePrimary: {
          'btn-primary': true, 
          active: true
        }
      }
    });
</script>

<button class="btn btn-primary active"></button>

<button v-bind:class="activeClass"></button>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        isActive: true
      },
      computed: {
        activeClass() {
          return {
            active: this.isActive
          }
        }
      }
    });
</script>

<button class="btn" v-bind:class="[primary, active]"></button>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        primary: 'btn-primary',
        active: 'btn-active'  
      }
    });
</script>

//Ternary expression <button v-bind:class="[isActive ? active : '', primary]"></button>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        isActive: true,
        primary: 'btn-primary',
        active: 'btn-active'  
      }
    });
</script>
 
//Using object syntax in an array <button v-bind:class="[{active: isActive}, primary]"></button>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        isActive: true,
        primary: 'btn-primary'
      }
    });
</script>

<div v-bind:style="{color: colorStyle, backgroundColor: background}">
Object syntax
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        colorStyle: 'red',
        background: 'blue'
      }
    });
</script>

<div v-bind:style="style">Object syntax</div>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        style: {
          color: 'red',
          backgroundColor: 'blue'
        }
      }
    });
</script>

<div v-bind:style="[style, fontStyle]">Object syntax</div>
<script>
    var vm = new Vue({
      el: "#app",
      data: {
        style: {
          color: 'red',
          backgroundColor: 'blue'
        },
        fontStyle: {
          fontSize: '18px'
        }
      }
    });
</script>