text: document.write("<h1>Tutorial no. 22 -- Array related methods in JS</h1>");
  
  //  concat method.
  // document.write("<h4>Array concat method</h4>")
  var arrOne = ["asif", "kawser", "muhsin", "noman", "tushar"];
  // document.write(arrOne);
  // document.write("<br>");
  
  // var stale = arrOne.concat("biplob", "saikat");
  // document.write("After concat : -- " + stale);
  
  //  Adding value by splice method
  document.write("<br><br>Adding value by splice() method<br>");
  
  arrOne.splice(2, 0, "rahim", "karim");
  document.write(arrOne);
  document.write("<br>")
  // sort() method. -- it sorts value by alphabetically.
  document.write("<br>sort() method:<br>")
  var arrSort = arrOne.sort();
  document.write(arrSort + "<br>");
  
  // Reverse sort method  
  document.write("<br>reverse() method<br>")
  var namereverse = arrOne.reverse();
  document.write(namereverse);
  
  // Number sorting method -- for sorting number sort() method can't use. to sort numbers, need a function. which value must be like a-b;
  document.write("<br><br>How to sort numbers<br>")
  var num = [5, 2, 20, 13, 3, 42, 8, 32, 1];
  
  num.sort(function(a, b){
      return a - b;
  })
  document.write(num);
  
  // Numbers reverse sorting method ---
  document.write("<br><br>Numbers reverse sorting method<br>")
  num.sort(function(a, b){
      return b - a;
  })
  document.write(num);
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  