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Firstly convert your number to hexadecimal with leading zeros and then format it by adding dashes.ExampleYou can try to run the following code to format hexadecimal number −Live Demo var num = 32122; var myHex = ("000000000000000" + num.toString(16)).substr(-16); var resHex = myHex.substr(0, 8)+'-'+myHex.substr(8,4)+'-'+myHex.substr(12,4); document.write(resHex); Output00000000-0000-7d7a
Use the toString() method to covert the Number to string, then the length() method gives you length.ExampleYou can try to run the following code to learn how to get the length of a Number −Live Demo var num1 = 344; var num2 = 149856; document.write("Length of number "+num1+" = "+ num1.toString().length); document.write("Length of number "+num2+" = "+ num2.toString().length); OutputLength of number 344 = 3 Length of number 149856 = 6
NaN is a JavaScript property, which is Not-a-Number value. This shows it is not a legal number. Here’s the syntax −SyntaxNumber.NaNTo find out whether a number is NaN, use the Number.isNaN() or isNan() method. Here’s an example to check −ExampleLive Demo Check function display() { var a = ""; a = a + isNaN(434) + ": 434"; a = a + isNaN(-23.1) + ": -23.1"; a = a + isNaN('Hello') + ": 'Hello'"; a = a + isNaN(NaN) + ": NaN"; a = a + isNaN('') + ": ''"; a = a + isNaN(0) + ": 0"; a = a + isNaN(false) + ": false"; document.getElementById("test").innerHTML = a; }
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);
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.
The largest possible value a number in JavaScript can have 1.7976931348623157E+308. The Number.MAX_VALUE property belongs to the static Number object. It represents constants for the largest possible positive numbers that JavaScript can work with.ExampleYou can try to run the following code to get the maximum value represented by Number object −Live Demo Click the following to see the result:
The with keyword is used as a kind of shorthand for referencing an object's properties or methods.The object specified as an argument to with becomes the default object for the duration of the block that follows. The properties and methods for the object can be used without naming the object.SyntaxThe syntax for with object is as follows −with (object){ properties used without the object name and dot }ExampleYou can try to learn the following code to learn how to implement with keyword −Live Demo User-defined objects ... Read More
The new operatorThe new operator is used to create an instance of an object. To create an object, the new operator is followed by the constructor method.In the following example, the constructor methods are Object(), Array(), and Date(). These constructors are built-in JavaScript functions.var department = new Object(); var books = new Array("C++", "Perl", "Java"); var day = new Date(“December 1, 2017");The object() constructorA constructor is a function that creates and initializes an object. JavaScript provides a special constructor function called Object() to build the object. The return value of the Object() constructor is assigned to a variable.The variable contains ... Read More
To pop-up a print dialog box using JavaScript, use the print() method. With the dialog box, you can easily set the printing options like which printer to select for printing.This is the dialog box −ExampleYou can try to run the following code to learn how to print a page −Live Demo Click to Print function display() { window.print(); }