Vue always tries to render elements as efficient as possible. So it tries to reuse the elements instead of building them from scratch. But this behavior may cause problems in few scenarios. For example, if you try to render the same input element in both v-if
and v-else
blocks then it holds the previous value as below,
<template v-if="loginType === 'Admin'">
<label>Admin</label>
<input placeholder="Enter your ID">
</template>
<template v-else>
<label>Guest</label>
<input placeholder="Enter your name">
</template>
In this case, it shouldn't reuse. We can make both input elements as separate by applying key attribute as below,
<template v-if="loginType === 'Admin'">
<label>Admin</label>
<input placeholder="Enter your ID" key="admin-id">
</template>
<template v-else>
<label>Guest</label>
<input placeholder="Enter your name" key="user-name">
</template>