title: How to get the required data types of function arguments in R Language?
body: <p>How do I get the data types of arguments of a function? Let me explain you with an example of the <code>cor</code> function.</p>
  
  <p><code>args(cor)</code> will display the argument list:</p>
  
  <pre><code>function (x, y = NULL, use = "everything", method = c("pearson", kendall", "spearman"))
  </code></pre>
  
  <p>How can I obtain get the data type required of <code>x</code> and <code>y</code> (e.g. <code>char</code>, <code>integer</code>, <code>list</code> et c)  before using it.</p>
  
  <p>and i need to save the data types as well.</p>