title: sass function not working
body: <p><strong><em>Any suggestion related to code will be appreciated :)</em></strong></p>
  
  <p><strong>function <em>str-remove-alphabet()</em></strong>:-
  this function takes one string as an argument.and remove any alphabet in that string.and return an int value.</p>
  
  <pre><code>// 3.str-alpha-remove function. removes alphabet from given string.   
  @function str-remove-alphabet($string) {                              
  // local variables.                                                 
  // loop alphabets list to index occurence of alphabets in string    
  @each $i in $list-alphabets {                                       
  // if occurence found.                                            
    @if(str-index($string, $i)) {                                     
      $string: str-replace($string, $i, '');                          
      @return $string; // than replace that character with null.      
    } @else {                                                         
      @return $string; // otherwise return string.                    
    }                                                                 
   }                                                                   
  }                                                                     
  </code></pre>
  
  <p><strong>function <em>font-size()</em></strong>:- 
  this function takes two argument.
  1.font-size and 2. unit. and converts font-size (eg 15px) and convert it into (eg 15) using str-remove-alphabet function. after successful return it start calculating font-size into given unit(eg 1.223342rem).</p>
  
  <pre><code>// 1.font-size calculator based on font-size given and unit.                   
  
  //noinspection CssInvalidFunction                                              
  
  @function font-size($size, $unit: 'em') {                                      
  $size: str-remove-alphabet('17px');                                          
  $base-font: str-remove-alphabet('15px');                                     
   @if($unit == 'em') {                                                         
     $font-size: ($size / $base-font) em;                                       
     @debug $font-size;                                                         
     @return $font-size; // returns font-size in em format                      
   } @else if($unit == 'per') {                                                 
     $font-size: ($size / $base-font) * 100%;                                   
     @debug $font-size;                                                         
     @return $font-size; // returns font-size in percentage format              
   } @else {                                                                    
     $font-size: ($size / $base-font) * 1rem;                                   
     @debug $font-size;                                                         
     @return $font-size; // else return in rem format                           
   }                                                                            
  
  }                                                                              
  </code></pre>
  
  <p><strong><em>problem</em></strong> :- i am unable to call str-remove-alphabet() inside of font-size().
  <a href="https://i.stack.imgur.com/SRcJm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SRcJm.png" alt="enter image description here"></a></p>