title: Making a vector with string elements
body: <p>I want to make the following vector with string elements:</p>
  
  <pre class="lang-r prettyprint-override"><code>L1  L1  L2  L2  L3  L3  L4  L4  L5  L5  L6  L6  L7  L7  L8  L8  L9  L9  L10  L10
  </code></pre>
  
  <p>To make this vector, I used the below code:</p>
  
  <pre class="lang-r prettyprint-override"><code>rep(c("L1","L1","L2","L2","L3","L3","L4","L4"),2)
  </code></pre>
  
  <p>But I think there is a shorter (easier or simpler) code than my code. Do you have any idea?</p>