先来个普通的数组：
<code class="hljs javascript has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">scala> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">var</span> arr=<span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">Array</span>(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.0</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span>,<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span>)<code class="hljs javascript h
