large string multiplication (v4)

Revision 4 of this benchmark created on March 21, 2011

Preparation HTML

<script>
  function stringMultiply1(string, n) {
   var temp = '';
   for (var i = 0; i < n; i++)
   temp += string;
   return temp;
  }
  
  function stringMultiply2(string, n) {
   var temp = string,
       x = Math.floor(Math.log(n) / Math.LN2);
   for (var i = 0; i < x; i++)
   string += string;
   for (var i = 0; i < (n - Math.pow(2, x)); i++)
   string += temp;
   return string;
  }
  
  function stringMultiply3(string, n) {
   var x = Math.floor(Math.log(n) / Math.LN2),
       temp = string;
   for (var i = 0; i < x; i++)
   string += string;
   return (n) ? string + stringMultiply3(temp, n - Math.pow(2, x)) : "";
  }
  
  function stringMultiply4(str, num) {
   var pre = [str],
       b = num.toString(2).split('').reverse(),
       l = b.length,
       i = 1;
   while (i < l) {
    var s = pre[i - 1];
    pre.push(s + s);
    i++;
   }
   var i = 0;
   while (i < l) {
    if (b[i] == '0') pre[i] = '';
    i++;
   }
   return pre.join('');
  }
</script>

Test runner

stringMultiply3("testing ", 1000);

stringMultiply2("testing ", 1000);

stringMultiply1("testing ", 1000);

stringMultiply4("testing ", 1000);

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

• Revision 4: published on March 21, 2011