Use Exact Search Term Only

Use Exact Search Term Only

I have a function that looks at search terms in a class and shows content that matches the term from an input.

The problem is, if I search for a1 and there's a term somewhere that's a12, then both are shown.
I want to limit the result to only exact matches.  Tried adding green text below, ie filter, but getting an undefined function.

  2. function HideFilter() { 
  3.     var txt = $('input#select_searcher_%id%').val();
  4.     txt = txt.toLowerCase();
  5.     $('[class^="searcher_stack-its"] span').filter("[class]").each(function() {
  6.       var x = ($(this).attr('class')).toLowerCase().filter(txt);
  7.       if ( x.indexOf(txt) >= 0 ) {  /* + 1 */
  8.         if ( x.indexOf(txt) != x.lastIndexOf(txt) ) {  // more than 1 match present - need to limit to exact match only
  9.           console.log('More than 1 match for ' + txt);
  10.         }
  11.         ... show matched content 
  12.       }  
  13.       else {
  14.         ... hide content that doesn't match
  15.       }  
  16.     });
  17.   }

Thanks,  Bill