javascript vs Delphi perf test. see here delphi code https://forums.embarcadero.com/thread.jspa?threadID=74930

gistfile1.js

function itg (x) { return x*x; }
 

var vp = 50000;
  var np = 0;
  var snp = np;
  var step = 0.0001;
  var sum = 0;
  console.log('Integral calculations...');
  var cnt1 = Date.now();
  while (np + step < vp) {
    //sum = sum + (itg(np) + itg(np + step)) / 2*step;
    sum = sum + ((np*np + (np + step)*(np + step))) / 2 * step;
    np = np + step;
  }
  var cnt2 = Date.now();
  var cnt3 = cnt2 - cnt1;
  console.log('Integral from ' + snp + ' to ' + vp +
                    ' step ' + step + ' is equal ' + sum +                    
                    'Difference: ' + (cnt3 / 1000) + ' seconds');