title: Convert a column in R data frame to lower case
body: <p>Here is my data </p>
  
  <pre><code>summary(RecordsWithIssues)
  ID             OTHERSTATE        OTHERCOUNTRY      
  Length:373         Length:373         Length:373        
  Class :character   Class :character   Class :character  
  Mode  :character   Mode  :character   Mode  :character
  
  &gt; head(RecordsWithIssues)
  # A tibble: 6 × 3
                    ID OTHERSTATE      OTHERCOUNTRY
                 &lt;chr&gt;      &lt;chr&gt;             &lt;chr&gt;
  1 0034000001uhro2AAA         MO              &lt;NA&gt;
  2 0034000001uhyOsAAI       &lt;NA&gt;          reseller
  3 0034000001uhyPJAAY       &lt;NA&gt;          AECbytes
  4 0034000001uhyPZAAY       &lt;NA&gt;            Friend
  5 0034000001uhyPeAAI       &lt;NA&gt;            client
  6 0034000001uhyPnAAI       &lt;NA&gt;     good energies
  </code></pre>
  
  <p>I do the following </p>
  
  <pre><code>RecordsWithIssues[,3]=tolower(RecordsWithIssues[,3])
  RecordsWithIssues[1,3]
  # A tibble: 1 × 1
                                                                                                               OTHERCOUNTRY
                                                                                                                      &lt;chr&gt;
  1 c(na, "reseller", "aecbytes", "friend", "client", "good energies", "boss", "friend", "linkedin", "aecbytes", "
  &gt; 
  </code></pre>
  
  <p>As you can see data frame now has a vector instead of single text value. How can I simply convert the string without getting the text </p>