ExampleTo parse JSON object in JavaScript, implement the following code −                    myData = JSON.parse('{"event1":{"title":"Employment period","start":"12\/29\/2011 10:20 ","end":"12\/15\/2013 00:00 "},"event2":{"title":"Employment period","start":"12\/14\/2011 10:20 ","end":"12\/18\/2013 00:00 "}}')          myArray = []          for(var e in myData){             var dataCopy = myData[e]             for(key in dataCopy){                if(key == "start" || key == "end"){                   dataCopy[key] = new Date(dataCopy[key])                }             }             myArray.push(dataCopy)          }          document.write(JSON.stringify(myArray));          

The conditional operator or ternary operator first evaluates an expression for a true or false value and then executes one of the two given statements depending upon the result of the evaluation.S.NoOperator & Description1? : (Conditional )If Condition is true? Then value X: Otherwise value YExampleYou can try to run the following code to understand how Ternary Operator works in JavaScriptLive Demo                    var a = 10;          var b = 20;          var linebreak = "";          document.write ("((a > b) ? 100 : 200) => ");          result = (a > b) ? 100 : 200;          document.write(result);          document.write(linebreak);          document.write ("((a < b) ? 100 : 200) => ");          result = (a < b) ? 100 : 200;          document.write(result);          document.write(linebreak);          

To pass a parameter to setTimeout() callback, use the following syntax −setTimeout(functionname, milliseconds, arg1, arg2, arg3...)The following are the parameters −function name − The function name for the function to be executed.milliseconds − The number of milliseconds.arg1, arg2, arg3 − These are the arguments passed to the function.ExampleYou can try to run the following code to pass a parameter to a setTimeout() callbackLive Demo           Submit                function timeFunction() {             setTimeout(function(){ alert("After 5 seconds!"); }, 5000);          }          Click the above button and wait for 5 seconds.    

To execute an anonymous function you need to use the leading bang! or any other symbol −!function(){    // do stuff }();You can also write it like −+function(){    // do stuff }();Even the following is an acceptable syntax −~function(){    // do stuff    return 0; }( );

To determine if an argument is sent to function, use “default” parameters.ExampleYou can try to run the following to implement itLive Demo                    function display(arg1 = 'Tutorials', arg2 = 'Learning') {             document.write(arg1 + ' ' +arg2+"");          }          display('Tutorials', 'Learning');          display('Tutorials');          display();          

To call multiple JavaScript functions in on click event, use a semicolon as shown below −onclick="Display1();Display2()"ExampleLive Demo                    function Display1() {             document.write ("Hello there!");          }          function Display2() {             document.write ("Hello World!");          }                     Click the following button to call the function                          

The JavaScript eval() is used to execute an argument. The code gets execute slower when the eval() method is used. It also has security implementations since it has a different scope of execution.ExampleHere’s how you can implement eval() function −                     var a = 30;          var b = 12;          var res1 = eval("a * b") + "";          var res2 = eval("5 + 10") + "";          document.write(res1);          document.write(res2);          

This tutorial will teach us to call a JavaScript function on page load. In many cases, while programming with HTML and JavaScript, programmers need to call a function, while loading the web page or after the web page load finishes. For example, programmers need to show the welcome message to the user on page load, and the programmer needs to call a JavaScript function after the page load event.There are various ways to call a function on page load or after page load in JavaScript, and we will look at them one by one in this tutorial.Using the onload event ... Read More

++a returns the value of an after it has been incremented. It is a pre-increment operator since ++ comes before the operand.a++ returns the value of a before incrementing. It is a post-increment operator since ++ comes after the operand.ExampleYou can try to run the following code to learn the difference between i++ and ++i −                       var a =10;           var b =20;           //pre-increment operator           a = ++a;           document.write("++a = "+a);                       //post-increment operator           b = b++;           document.write(" b++ = "+b);          

Using “javascript:void(0)” is definitely better, since its faster. Try to run both the examples in Google Chrome with the developer tools. The “javascript:void(0)” method takes less time than the only #.Here’s the usage of “javascript: void(0)”:If inserting an expression into a web page results in an unwanted effect, then use JavaScript void to remove it. Adding “JavaScript:void(0)”, returns the undefined primitive value.The void operator is used to evaluate the given expression. After that, it returns undefined. It obtains the undefined primitive value, using void(0).The void(0) can be used with hyperlinks to obtain the undefined primitive valueExampleLive Demo     ... Read More