Check out example codes for "vue pick 20 items from array". It will help you in understanding the concepts better.

Code Example 1

<div v-if="showLess">
  <div v-for="value in array.slice(0, 20)"></div>
</div> 
<div v-else> 
  <div v-for="value in array"></div>
</div> 
<button @click="showLess = false"></button>

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