Page 162 - DCAP408_WEB_PROGRAMMING
P. 162

Web Programming




                    Notes                 var  s=today.getSeconds();
                                          //  add  a  zero  in  front  of  numbers<10
                                          m=checkTime(m);
                                          s=checkTime(s);
                                          document.getElementById(‘txt’).innerHTML=h+”:”+m+”:”+s;
                                          t=setTimeout(‘startTime()’,500);
                                          }
                                          function  checkTime(i)
                                          {
                                          if  (i<10)
                                            {
                                              i=”0"  +  i;
                                            }
                                          return  i;
                                          }
                                          </script>
                                          </head>
                                          <body  onload=”startTime()”>
                                          <div  id=”txt”></div>
                                          </body>
                                          </html>
                                   Output
                                          15:50:23

                                   5.7.3 Boolean Object

                                   The Boolean object represents two values: “true” or “false”.
                                   The following code creates a Boolean object called myBoolean:
                                          var myBoolean=new Boolean();

                                   Note: If the Boolean object has no initial value or if it is 0, -0, null, “”, false, undefined, or NaN,
                                   the object is set to false. Otherwise it is true (even with the string “false”)!
                                   All the following lines of code create Boolean objects with an initial value of false:

                                          var myBoolean=new Boolean();
                                          var myBoolean=new Boolean(0);
                                          var myBoolean=new Boolean(null);

                                          var myBoolean=new Boolean(“”);
                                          var myBoolean=new Boolean(false);
                                          var myBoolean=new Boolean(NaN);






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