You can see the following example for cocatenating
<div class="wrapper" v-bind:key="index" v-for="(obj, index) in phones">
<input :id="'id_'+index" name="a11y-issues" v-model="seleted_phone" type="radio" :value="obj.id" />
</div>
This is how you do it
:id="'id_'+index"
You can’t use curly bracket (moustache tags) in attributes.
See how src
of the image has been concatenated with variable and text
<img v-bind:src="imgPath + 'img/logo.png'">