What is callback and promise in JavaScript?
Callback: A callback is a function that is passed as an argument to another function and is executed after its parent function has completed. A callback is used to extend the functionality of a given function, by allowing the user to add their own code before or after the original function runs.
Promise: A Promise is an object representing the eventual completion or failure of an asynchronous operation. In simpler terms, Promises represent the result of an asynchronous task, which can either resolve (successful completion) or reject (unsuccessful completion) a certain value. Promises allow for better asynchronous code by making the code simpler and easier to debug, due to the explicit feedback on the success or failure of the asynchronous operation.
Date:2023-03-05
How to remove things from arrays in JavaScript?
You can use the pop() or shift() methods to remove elements from the beginning or end of an array respectively. You can also use the splice() method to remove elements from specific positions in the array. To remove specific values from an array, use the filter() method.
Date:2023-03-05
Why were default and static methods added to interfaces in Java 8?
Default and static methods were added to interfaces in Java 8 to allow developers to add new functionality to existing interfaces without breaking existing code. By making existing methods in interfaces default or static, developers can easily create backwards compatible interfaces that maintain a consistent API. This makes it easier to add functionality to existing interfaces, eliminating the need to change existing code or create new subclasses.
Date:2023-03-04
What is properties in Java?
Properties in Java are key-value pairs that describe the configuration of a Java program. They are typically used to store information about the program, such as its version number or the location of certain files. Properties are stored in an external file using a format that can be read by both humans and machines. The information stored in a properties file can then be retrieved and used by the program at runtime.
Date:2023-03-04
How can you create a checkbox using JavaScript?
You can create a checkbox using JavaScript by creating an HTML element such as <input type="checkbox" id="myCheckbox" /> and then using the JavaScript createElement() method to create the element on the page:
var checkbox = document.createElement("input");
checkbox.type = "checkbox";
checkbox.id = "myCheckbox";
document.body.appendChild(checkbox);
Date:2023-03-04
What was the first JavaScript engine?
The first JavaScript engine was the SpiderMonkey engine, which was introduced in 1995. It was developed by Brendan Eich and released as part of Netscape Navigator 2.0.
Date:2023-03-04
How to fetch the values of dynamic textboxes created using JavaScript?
If your textboxes are all given unique ids, you can use document.getElementById(theId) and receive the value of the textbox. If you need to iterate through all of the textboxes, you can use document.querySelectorAll("input[type=text]") and loop through them, accessing the value by accessing the value property of the specific DOM element.
Date:2023-03-04
Why is Safari so bad at rendering JavaScript?
Safari is generally slower than other browsers at rendering JavaScript because it doesn't make as much use of JIT (Just-in-Time) compilation, which is a key component of modern web browser performance. Safari also does not have as many features as other browsers when it comes to things like HTML5, so it can struggle with more complex websites. Other browsers, such as Chrome and Firefox, have had more years of development, leading to faster and more efficient use of JavaScript.
Date:2023-03-04
What are the basic Java programs?
1. Hello World
2. Palindrome Checker
3. Prime Number Checker
4. Chessboard Pattern Printing
5. String Reversal
6. Binary Search Algorithm
7. Fibonacci Series
8. Factorial Program
9. Calculate Area And Circumference
10. Guess the Number
Date:2023-03-04