What do you understand by Virtual DOM?
Think of the Virtual DOM like a draft version of your web page. Instead of changing the actual page (which is slow), React updates this lightweight copy first. Then, it smartly compares the draft with the real page and updates only the necessary parts kind of like editing a document without retyping the whole thing.
Result? Faster updates, smoother performance, and a better user experience! 🚀
Think of the Virtual DOM like a draft version of your web page. Instead of changing the actual page (which is slow), React updates this lightweight copy first. Then, it smartly compares the draft with the real page and updates only the necessary parts kind of like editing a document without retyping the whole thing.
Result? Faster updates, smoother performance, and a better user experience! 🚀
👍2
In C, if we pass an array as an argument to a function, what actually get passed?
Anonymous Quiz
20%
Address of the last element of array
46%
Base address of the array
20%
Value of elements in array
14%
First element of the array
Browser to Virtual DOM.png
37.2 KB
Virtual DOM works in three steps:
1. Whenever any data changes in the React App, the entire UI is re-rendered in Virtual DOM representation.
1. Whenever any data changes in the React App, the entire UI is re-rendered in Virtual DOM representation.
👍2
Virtual DOM and Real DOM.png
46.2 KB
2. Now, the difference between the previous DOM representation and the new DOM is calculated.
👍1
Real DOM.png
28.2 KB
3. Once the calculations are completed, the real DOM updated with only those things which are changed.
👍2
How React's ES6 syntax is different from ES5 syntax?
1. require vs. Import
1. require vs. Import
// ES5
var React = require('react');
// ES6
import React from 'react';
👍1
2. exports vs. export
// ES5
module.exports = Component;
// ES6
export default Component;
3. component and function
// ES5
var MyComponent = React.createClass({
render: function() {
return(
<h3>Hello JavaTpoint</h3>
);
}
});
// ES6
class MyComponent extends React.Component {
render() {
return(
<h3>Hello Javatpoint</h3>
);
}
}
👍1
4. props
// ES5
var App = React.createClass({
propTypes: { name: React.PropTypes.string },
render: function() {
return(
<h3>Hello, {this.props.name}!</h3>
);
}
});
// ES6
class App extends React.Component {
render() {
return(
<h3>Hello, {this.props.name}!</h3>
);
}
}
Python Complete Tutorial By Guido Van Rossum and Team.pdf
628.6 KB
Python Complete Tutorial by Guido Van Rossum and Team
👍3
Common Coding Mistakes to Avoid
Even experienced programmers make mistakes.
Ensure all variables are declared and initialized before use.
Be mindful of JavaScript's automatic type conversion, which can lead to unexpected results.
Understand the difference between global and local scope to avoid unintended variable access.
Carefully review your code for logical inconsistencies that might lead to incorrect output.
Pay attention to array indices and loop conditions to prevent errors in indexing and iteration.
Avoid creating loops that never terminate due to incorrect conditions or missing exit points.
Example:
// Undefined variable error
let result = x + 5; // Assuming x is not declared
// Type coercion error
let age = "30";
let isAdult = age >= 18; // Age will be converted to a number
By being aware of these common pitfalls, you can write more robust and error-free code.
Do you have any specific coding mistakes you've encountered recently?
Even experienced programmers make mistakes.
Undefined variables:
Ensure all variables are declared and initialized before use.
Type coercion:
Be mindful of JavaScript's automatic type conversion, which can lead to unexpected results.
Incorrect scope:
Understand the difference between global and local scope to avoid unintended variable access.
Logical errors:
Carefully review your code for logical inconsistencies that might lead to incorrect output.
Off-by-one errors:
Pay attention to array indices and loop conditions to prevent errors in indexing and iteration.
Infinite loops:
Avoid creating loops that never terminate due to incorrect conditions or missing exit points.
Example:
// Undefined variable error
let result = x + 5; // Assuming x is not declared
// Type coercion error
let age = "30";
let isAdult = age >= 18; // Age will be converted to a number
By being aware of these common pitfalls, you can write more robust and error-free code.
Do you have any specific coding mistakes you've encountered recently?
👍6