Yes, it’s possible and there is nothing much programmers have to do to access it. It is actually the most common method used by the developers when it comes to conversion
Posted Date:- 2021-08-23 09:32:14
Blur function is used to remove the focus from the specified object.
Posted Date:- 2021-08-23 09:31:34
Yes, basically many times a programmer has to enter the input values directly through the text box. The prompt box is something that is extremely helpful for the users during such a situation. Label and the box are provided for the ease of programmers. They are basically used for entering the number or the text simply.
Posted Date:- 2021-08-23 09:30:49
Try… Catch---finally is used to handle exceptions in the JavaScript
Try{
Code
}
Catch(exp){
Code to throw an exception.
}
Finally{
Code runs either it finishes successfully or after catch
}
Posted Date:- 2021-08-23 08:56:42
An alert box displays only one button, which is the OK button.
But a Confirmation box displays two buttons, namely OK and cancel.
Posted Date:- 2021-08-23 08:55:56
1. Alert
2. Confirm and
3. Prompt
Posted Date:- 2021-08-23 08:55:18
Undefined value means the
Variable used in the code doesn't exist
Variable is not assigned to any value
Property does not exist
Posted Date:- 2021-08-23 08:54:18
The delete keyword is used to delete the property as well as its value.
Example
var student= {age:20, batch:"ABC"};
Delete student. age;
Posted Date:- 2021-08-23 08:53:36
In order to detect the operating system on the client machine, the navigator. Platform string (property) should be used.
Posted Date:- 2021-08-23 08:52:39
Since 3 and 2 are integers, they will be added numerically. And since 7 is a string, its concatenation will be done. So the result would be 57.
Posted Date:- 2021-08-23 08:51:58
Following are looping structures in Javascript:
a) For
b) While
c) Do-while loops
Posted Date:- 2021-08-23 08:51:23
There are two ways to read and write a file using JavaScript
1. Using JavaScript extensions
2. Using a web page and Active X objects
Posted Date:- 2021-08-23 08:50:08
Timers are used to execute a piece of code at a set time or repeat the code in a given interval. This is done by using the functions setTimeout, setInterval, and clearInterval.
The setTimeout(function, delay) function is used to start a timer that calls a particular function after the mentioned delay. The setInterval(function, delay) function repeatedly executes the given function in the mentioned delay and only halts when canceled. The clearInterval(id) function instructs the timer to stop.
Timers are operated within a single thread, and thus events might queue up, waiting to be executed.
Posted Date:- 2021-08-23 08:47:23
There are variables in the language that generally doesn’t have much scope or their scope is limited. In JavaScript, Global variables are the same variables. To declare them, the keyword that can be used is var. the fact is most of the programmers avoid using this variable due to a major issue and i.e. the strong chances of clashing of variable names with the global, or with the local group. F course, it leads to many issues. In addition to this, there are certain chances of debugging issues that declare their presence with the global variables.
Posted Date:- 2021-08-23 08:46:16
When it comes to speed, both of them are powerful but both have their own limits that put them separate from one another. JavaScript is known to have a quick speed for performing similar functions. This is because JavaScript doesn’t need the help of a web server to perform the task which is assigned to it. However, ASP is slow as compare to it. This is because of the very same reason and i.e. it depends largely on the webserver for executing the tasks assigned to it. Although the server-side version of JavaScript i.e. node.js also exists, still it is known to provide quick results.
Posted Date:- 2021-08-23 08:45:19
isNan function is useful in case the argument is not a number. Actually, it remains true if the argument doesn’t have a number while on the other side it remains false if it is.
Posted Date:- 2021-08-23 08:44:28
isNan function is useful in case the argument is not a number. Actually, it remains true if the argument doesn’t have a number while on the other side it remains false if it is.
Posted Date:- 2021-08-23 08:43:45
IIFEs (Immediately Invoked Function Expressions), also called Self-Executing Anonymous Functions, are functions that execute immediately after their definition. These are also a design pattern that contains two major parts:
The first part is an anonymous function with a lexical scope enclosed within the Grouping operator (). This restricts the access of variables within the IIFE idiom and prevents it from polluting the global scope.
The second part of IIFE creates the immediately executing function expression, through which the JavaScript engine will directly interpret the function.
The syntax of an IIFE is as follows:
(function () {
statements
})();
Posted Date:- 2021-08-23 08:41:28
You will find 3 types of Popup boxes available in JavaScript:
Confirm
Alert
Prompt
Posted Date:- 2021-08-23 08:39:33
The thumb rule for functions in ES6 and beyond is as follows:
a) Use functions in the global scope and for Object.prototype properties.
b) Use class for object constructors.
c) Use => everywhere else.
Posted Date:- 2021-08-23 08:38:59
No matter what button the user clicks, the output will always be 5. This is because when the onclick event invokes (when the user clicks any of the buttons), the ‘for’ loop is already finished and the value of the variable i is set to 5. All this happens at the time the document loads; the onclick event occurs later.
Posted Date:- 2021-08-23 08:38:01
In JavaScript, whenever we require to transform a variable from one data to another, then Typecasting is used. Besides, we can do this through library functions. There are mainly 3 typecasts that you will see in JavaScript Programming:
Boolean(value): Casts the inputted value to a Boolean
Number(value): Casts the inputted value to a Floating point Number or an Integer.
String(value) : Casts the inputted value value a string
Posted Date:- 2021-08-23 08:35:27
“Use Strict†is a JavaScript directive that was launched in Es5. The main purpose of using this directive is to enforce the code is performed in strict mode. In this mode, we cannot use a variable without proclaiming it. This directive is ignored by the previous versions of JavaScript.
Posted Date:- 2021-08-23 08:34:38
There is a lot of cool stuff available in JavaScript and one of them is Delegation model. When you are bubbling and capturing, it permit functions to apply a single handler to several elements at a specific time then it’s called Event Delegation. It basically permits you to put event listeners to single parent instead of particular nodes. That specific listener analyzes the bubbled events to get a match on the child elements. Several individuals think it to be daunting job but in reality, it seems easy if one begins to understand it.
Posted Date:- 2021-08-23 08:34:11
To understand the differences between the two, let’s look at what each function does.
forEach
Iterates through the elements in an array.
Executes a callback for each element.
Does not return a value.
const a = [1, 2, 3];
const doubled = a.forEach((num, index) => {
// Do something with num and/or index.
});
// doubled = undefined
map
Iterates through the elements in an array.
“Maps†each element to a new element by calling the function on each element, creating a new array as a result.
const a = [1, 2, 3];
const doubled = a.map(num => {
return num * 2;
});
// doubled = [2, 4, 6]
The main difference between .forEach and .map() is that .map() returns a new array. If you need the result, but do not wish to mutate the original array, .map() is the clear choice. If you simply need to iterate over an array, forEach is a fine choice.
Posted Date:- 2021-08-23 08:31:49
Set objects are used to store different values to the elements. The values may be a reference or primitive values.
function display()
{
var set = new Set();
set.add( "Angular JS":;
set.add(" Vue");
set.add("React JS);
for(set the elements of set)
{
doc.writeIn(elements):
}
}
display();
Posted Date:- 2021-08-23 08:25:53
Number objects help to represent the number of values to the variables. The values may be floating-point or integer. In JavaScript, the floating points are represented by using the IEEE standard.
function display()
{
var a = 10;
var b = 0.7;
var c = 11d5;
doc.write(a+" "+b+" "+c+");
}
display();
Posted Date:- 2021-08-23 08:25:01
var Employee =
{
company: 'xyz'
}
var Emp1 = Object.create(employee);
delete Emp1.company Console.log(emp1.company);
The output would be xyz. Here, emp1 object has company as its prototype property. The delete operator doesn’t delete prototype property. emp1 object doesn’t have company as its own property. However, we can delete the company property directly from the Employee object using delete Employee.company.
Posted Date:- 2021-08-23 08:23:42
Weakmap is similar to a collection of objects like a map. If the weak map object is set to a process, it considers each element as a key object and that key object will have a weak reference.
function display()
{
var wm = new WeakMap();
var object1 = {};
var object2 = {};
var object3 = {};
wm.set(object1, "AngularJS");
wm.set(object2, "ReactJS");
wm.set(object3, "VueJS");
doc.writeIn(wm.has(object3));
}
display();
Posted Date:- 2021-08-23 08:21:20
MUL is a multiplication function. The multiplication of numbers can be done as a value is defined in the function and the value is returned by another function and the process goes on.
Example:
function mul(a)
{
return function(b)
{
return function(c)
{
return a*b*c;
};
};
}
Posted Date:- 2021-08-23 08:20:24
To put it simple, generator has two features:
one can choose to jump out of a function and let outer code to determine when to jump back into the function.
the control of asynchronous call can be done outside of your code
The most important feature in generators — we can get the next value in only when we really need it, not all the values at once. And in some situations it can be very convenient.
Posted Date:- 2021-08-23 08:19:10
Generators are functions which can be exited and later re-entered. Their context (variable bindings) will be saved across re-entrances. Generator functions are written using the function* syntax. When called initially, generator functions do not execute any of their code, instead returning a type of iterator called a Generator. When a value is consumed by calling the generator's next method, the Generator function executes until it encounters the yield keyword.
The function can be called as many times as desired and returns a new Generator each time, however each Generator may only be iterated once.
function* makeRangeIterator(start = 0, end = Infinity, step = 1) {
let iterationCount = 0;
for (let i = start; i < end; i += step) {
iterationCount++;
yield i;
}
return iterationCount;
}
Posted Date:- 2021-08-23 08:18:21
There are two ways in which we can remove duplicates from a JavaScript array:
An empty array is used for storing all the repeating elements.
By Using the Filter Method
To call the filter() method, three arguments are required. These are namely array, current element, and index of the current element.
By Using the For Loop
Posted Date:- 2021-08-23 08:16:59
Many JavaScript libraries use this technique. It helps to develop a closure around the contents of the file which helps to create a private namespace and hence, avoid any name clash with different JavaScript modules and libraries.
Posted Date:- 2021-08-23 08:14:07
//nfe (named function expression)
var Foo = Function Bar()
{
return 7;
};
typeof Bar();
Output = Reference Error. The function definition can only have one reference variable as the function name.
Posted Date:- 2021-08-23 08:13:44
The call() method helps to call a function which has a given ‘this’ value and the arguments which are individually provided. The syntax is:
fun.call(thisArg[, arg1[, arg2[, …]]])
The apply() method is used to call a function which has a given ‘this’ value but the arguments are presented as an array. The syntax is:
fun.apply(thisArg, [argsArray])
Posted Date:- 2021-08-23 08:12:55
The prompt box in JavaScript helps the user to input with the help of a text box. The prompt() method helps to display the dialog box which prompts the visitor to provide an input.
Posted Date:- 2021-08-23 08:11:43
Since 2 and 5 are integers, normal addition will be executed. 3 however is a string and hence, there will be concatenation. Ҡrepresents a string.
Posted Date:- 2021-08-23 08:11:11
By using the parseInt() function, you can transform numbers among different bases.
Posted Date:- 2021-08-23 08:10:44
Window is a global object and it holds functions, variables, location and history.
Document is a part of the window and is deemed as a property of the Javascript window.
Posted Date:- 2021-08-23 08:09:33
Local Storage – In local storage, the data will not be returned to the server at every HTTP request (images, HTML, CSS, JavaScript, etc). It helps to reduce the traffic between server and client.
Session Storage – Session Storage is quite similar to the local storage. However, unlike data storage in local systems which has an expiry time, data stored using session storage gets cleared once the page session ends.
Posted Date:- 2021-08-23 08:07:56
In Typed Language, values are associated with values alone. They are not associated with variables. There are two types of Typed Language:
Dynamically: For Dynamically Typed language, the variable can hold several types.
Statically: In Statically Typed languages, the variable is capable of holding only one type.
Posted Date:- 2021-08-23 08:07:15
<script type="text/javascript">
function addNode() {
var newP = document.createElement("p");
var textNode = document.createTextNode(" This is a new text node");
newP.appendChild(textNode); document.getElementById("firstP").appendChild(newP);
}
</script>
Posted Date:- 2021-08-23 08:01:51
Strict mode in JavaScript introduces more stringent error-checking in a JavaScript code.
a) While in Strict mode, all variables have to be declared explicitly, values cannot be assigned to a read-only property, etc.
b) We can enable strict mode by adding ‘use strict’ at the beginning of a JavaScript code, or within a certain segment of code.
Posted Date:- 2021-08-23 08:00:52
Both let and var are used for variable and method declarations in JavaScript. So there isn’t much of a difference between these two besides that while var keyword is scoped by function, the let keyword is scoped by a block.
Posted Date:- 2021-08-23 07:59:39
There are primarily two ways of embedding JavaScript code:
We can write JavaScript code within the script tag in the same HTML file; this is suitable when we need just a few lines of scripting within a web page.
We can import a JavaScript source file into an HTML document; this adds all scripting capabilities to a web page without cluttering the code.
Posted Date:- 2021-08-23 07:59:09
The ‘this’ keyword in JavaScript refers to the currently calling object. It is commonly used in constructors to assign values to object properties.
Posted Date:- 2021-08-23 07:57:10
These are the advantages of JavaScript:
Enhanced Interaction
JavaScript adds interaction to otherwise static web pages and makes them react to users’ inputs.
a) Quick Feedback
There is no need for a web page to reload when running JavaScript. For example, form input validation.
b) Rich User Interface
JavaScript helps in making the UI of web applications look and feel much better.
c) Frameworks
JavaScript has countless frameworks and libraries that are extensively used for developing web applications and games of all kinds.
Posted Date:- 2021-08-23 07:53:25
These are the different types of data that JavaScript supports:
Boolean - For true and false values
Null - For empty or unknown values
Undefined - For variables that are only declared and not defined or initialized
Number - For integer and floating-point numbers
String - For characters and alphanumeric values
Object - For collections or complex values
Symbols - For unique identifiers for objects
Posted Date:- 2021-08-23 07:49:02
JavaScript is a popular web scripting language and is used for client-side and server-side development. The JavaScript code can be inserted into HTML pages that can be understood and executed by web browsers while also supporting object-oriented programming abilities.
Posted Date:- 2021-08-23 07:48:24