title: SAS function difference with double quotes and single quotes parameter string
body: <p>in Sas, below case 1 with single quotes works well, but case 2 with double quotes string parameters </p>
  
  <pre><code>case 1:
      data _null_;
      a = lowcase('ABC');
      run;
  
  case 2:
      data _null_;
      a = lowcase("ABC");
      run;
  
  825   data _null_;
  826   a = lowcase("ABC");
                    -
                    386
                    200
                    76
  ERROR 386-185: Expecting an arithmetic expression.
  ERROR 200-322: The symbol is not recognized and will be ignored.
  ERROR 76-322: Syntax error, statement will be ignored.*
  
  827   run;
  </code></pre>