To get dates in JavaScript, use the getTime() method. Forgetting the difference between two dates, calculate the difference between date and time.ExampleYou can try to run the following code to learn how to calculate a difference between two dates −Live Demo                    var dateFirst = new Date("11/25/2017");          var dateSecond = new Date("11/28/2017");          // time difference          var timeDiff = Math.abs(dateSecond.getTime() - dateFirst.getTime());          // days difference          var diffDays = Math.ceil(timeDiff / (1000 * 3600 * 24));          // difference          alert(diffDays);          

Here’s the best way to read cookies by name in JavaScript. The following is the function −function ReadCookie() {    var allcookies = document.cookie;    document.write ("All Cookies : " + allcookies );    // Get all the cookies pairs in an array    cookiearray = allcookies.split(';');    // Now take key value pair out of this array    for(var i = 0; i < cookiearray.length; i++) {       name = cookiearray[i].split('=')[0];       value = cookiearray[i].split('=')[1];       document.write ("Key is : " + name + " and Value is : " + value);    } }

To generate a random number, we use the Math.random() function. This method returns a floating-point number in the range 0 (inclusive) to 1 (exclusive). To generate random numbers in different range, we should define the minimum and maximum limits of the range. Please follow the second syntax below for this. To generate random integers, you can follow the third and fourth syntax discussed below. As the Math.random() method gives us a random floating point number so to convert the result into an integer, we need to apply some basic math. Please follow the below syntaxes. Syntax Following is the syntax ... Read More

The standard Unix epoch is an expression in seconds. The Unix epoch or Unix time is the number of seconds elapsed since January 1, 1970.The getTime() method is used to return the millisecond representation of the Date object.To get time in milliseconds, use the following:var milliseconds = (new Date).getTime();

To get an integer in the string “abcde 30”, use the following regex in JavaScript, else it will return NaN. With that, use parseInt() to get the numbers with regex under String match() method −ExampleLive Demo                    var myStr = "abcdef 30";          var num = parseInt(myStr.match(/\d+/))          alert(num);          

Use the toString() method to get the string representation of a number. You can try to run the following code to print a string representation of numbers like 20, -40, 15.5 −ExampleLive Demo                    var num1 = 25;          document.write(num1.toString()+"");          document.write((30.2).toString()+"");          var num2 = 3;          document.write(num2.toString(2)+"");          document.write((-0xff).toString(2));           Output25 30.2 11 -11111111Above, you can see we added a parameter to the toString() method. This is an optional parameter, which allows you to add an integer between 2 and 36, which is the base for representing numeric values.

To create a session only cookie, you need to set the expiration date of the cookie to be some years ahead. You need to set the expire attribute −current time + 5 yearsThe expire attribute shows the date the cookie will expire. If this is blank, the cookie will expire when the visitor quits the browser.Note − Do not consider removing the expire value to create a session only cookie. This won’t work. Set the expire attribute to the future date.

In JavaScript, the NaN property is a special value that represents "Not a Number". It is a property of the Number object and can be accessed using Number.NaN. The NaN property is usually produced as a result of an operation that cannot produce a meaningful result. For example, dividing 0 by 0 or trying to parse an invalid number will both produce NaN. Here are a few examples of operations that will produce NaN − Math.sqrt(-1); // NaN 0/0; // NaN parseInt("foo"); // NaN It ... Read More

To store large values in JavaScript cookies, try the following possibilities −Create a "session id" and save the settings in a database. Then store the session id in the cookie.Store the indexes of the selected items. Let’s say the selected items are the first 20 items on the list −P[0,19]Create a table to store cookies data such as −[ data_id , data , data_create , date_expire ]Store data_id in a table and when a user visits, get the data_id in cookies.

While creating a cookie, use the “path” parameter. The path to the directory or web page set the cookie. This may be blank if you want to retrieve the cookie from the current page. By default, the cookie belongs to the current page.ExampleTo list all cookies for the current page, try the following code −Live Demo                    function ReadCookie() {             var allcookies = document.cookie;             document.write ("All Cookies : " + allcookies );             // Get all the cookies pairs in an array             cookiearray = allcookies.split(';');             // Now take key value pair out of this array             for(var i=0; i