vue js default props

JavaScript
props: {
  year: {
    default: 2016,
    type: Number
  }
}<!-- Even though the array is static, we need v-bind to tell Vue that -->
<!-- this is a JavaScript expression rather than a string.            -->
<blog-post v-bind:comment-ids="[234, 266, 273]"></blog-post>

<!-- Dynamically assign to the value of a variable. -->
<blog-post v-bind:comment-ids="post.commentIds"></blog-post>
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