When using vue, when binding vue variables to the attributes of the html tag, you should use v-bind (you can also use its abbreviation ":"). In your example, it should be
<div v-bind:class="classvalue">……</div>
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When using vue, when binding vue variables to the attributes of the html tag, you should use v-bind (you can also use its abbreviation ":"). In your example, it should be
<div v-bind:class="classvalue">……</div>