In this tutorial, we are going to learn how can we delay a function in JavaScript. Whenever we want to call a function after a specified amount of time than we use the delay function in JavaScript. To provide delay in JavaScript function we use a global window object named as setTimeout(). This function allows us to provide a specific delay before executing a function. Let’s deep down into some of the functionalities, syntax and many other things of setTimeout() function. The setTimeout() method mainly require two one is the function which we need to execute with some delay and ... Read More

We use Object and Map classes to mimic the behavior of associative array/hashing in JavaScript. JavaScript doesn’t provide an associative array built-in. The closest similar behavior we get is from the Map class in JavaScript. Let us look at them one by one. Object class in JavaScript The object class allows us to create objects with name-value pairs. This is similar to hashing as the object knows which property is associated with what value. Syntax const obj = { name : "Abhishek", age : 22 } var name = obj.name This creates an ... Read More

As we know, a URL is a web address. What is URL encodingand why do we need to encode a URL? The process of turning a string into an accurateURL format is known as URL encoding. A valid URL format only uses "alpha | digit | safe | extra | escape" characters. Only a limited selection of the normal 128 ASCII characters is permitted in URLs. It is required to encrypt reserved characters that are not part of this set. The reliability and security of the URLs are increased with URL encoding. Each character that needs to be URL-encoded is ... Read More

The increment (++) and decrement (---) operators should be avoided since it can lead to unexpected results. Here are some of the conditions −ExampleIn an assignment statement, it can lead to unfavorable results −Live Demo                                        var a = 5;                    var b = ++a;                    var c = a++;                    var d = ++c;                        document.write(a);                    document.write("\r"+b);                    document.write("\r"+c);                    document.write("\r"+d);                           OutputWhitespace between the operator and variable can also lead to unexpected results −a = b = c = 1; ++a ; b -- ; c;

In this tutorial, we will learn how to decode a URL using JavaScript. URL is an abbreviation for Uniform Resource Locator. A URL is the address of a certain Web site. Each valid URL, in principle, links to a different resource. These resources include an HTML page, a CSS document, a picture, etc. There are several exceptions in practice, the most frequent being a URL linking to a resource that no longer exists or has migrated. Because the Web server handles both the resource represented by the URL and the URL itself, it is up to the web server's owner ... Read More

The parseInt() method in JavaScript converts a string into a number. The method returns NaN if the value entered cannot be converted to a number.ExampleYou can try to run the following code to convert a string into an integer − Live Demo           Check                      function display() {             var val1 = parseInt("50") + "";             var val2 = parseInt("52.40") + "";             var val3 = parseInt(" 75 ") + "";             var res = val1 + val2 + val3;             document.getElementById("demo").innerHTML = res;          }          

In this tutorial, let us discuss how to validate a given number in JavaScript. Users can follow the syntax below each method to use it. Using regular expression The method tests or matches the regular expression with the input. Syntax /\D/.test(input); input.match(/^[0-9]*$/); If the input is a number, the test returns true. Example The program succeeds in all cases except for "30", [], and "". Number validation using regular expression Validate ... Read More

To add a number of months to a date, first get the month using getMonth() method and add a number of months.ExampleYou can try to run the following code to add a number of monthsLive Demo                    var d, e;          d = new Date();          document.write(d);          e = d.getMonth()+1;          document.write("Incremented month = "+e);          

Function DeclarationThe “function” keyword declares a function in JavaScript. To define a function in JavaScript use the “function” keyword, followed by a unique function name, a list of parameters (that might be empty), and a statement block surrounded by curly braces.Here’s an example −function sayHello(name, age) {    document.write (name + " is " + age + " years old."); }Function ExpressionFunction Expression should not start with the keyword “function”. Functions defined can be named or anonymous.Here are the examples −//anonymous function expression var a = function() {    return 5; }Or//named function expression var a = function bar() {    return 5; }

Double equals (==) is abstract equality comparison operator, which transforms the operands to the same type before making the comparison. For example,5 ==  5       //true '5' == 5      //true 5 == '5'      //true 0 == false    //trueTriple equals (===) are strict equality comparison operator, which returns false for different types and different content.For example,5 === 5  // true 5 === '5' // false var v1 = {'value':'key'}; var v2 = {'value': 'key'}; v1 === v2 //false