text: var i = 100;
  var iarr = [1, 2, 3];
  var s2 = '';
  var j = 99;
  addj(iarr);
  for (var j = 0; j < iarr.length; ++j) {
    var s1 = 'Hello';
    s2 = s1;
    i = j;
    console.log(iarr[j]);
  }
  console.log(s1);
  var s1 = 'World';
  console.log(s1, s2);
  console.log('i=', i);
  console.log('j=', j);
  j = 0;
  function addj(arr) {
    console.log('j=', j);
    for (var k = 0; k < arr.length; ++k) {
      arr[k] += j;
    }
    console.log('k=', k);
  }
  