title: Lua table.concat
body: <p>Is there a way to use the arg 2 value of table.concat to represent the current table index?</p>
  
  <p>eg:</p>
  
  <pre><code> t = {}
   t[1] = "a"
   t[2] = "b"
   t[3] = "c"
  
   X = table.concat(t,"\n")
  </code></pre>
  
  <p>desired output of table concat (X):</p>
  
  <pre><code> "1 a\n2 b\n3 c\n"
  </code></pre>