javascript advanced concepts
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Javascript Advanced Concepts#
Javascript is a powerful language that is used to build interactive web applications. However, to become a proficient Javascript developer, one must have a good understanding of advanced concepts. In this post, I will discuss some of the most important Javascript advanced concepts.
Closures#
A closure is an inner function that has access to the outer function's variables and parameters. It allows you to create private variables and methods in Javascript. Here is an example:
function outerFunction() {
const outerVariable = 'I am an outer variable';
function innerFunction() {
console.log(outerVariable);
}
return innerFunction;
}
const innerFunction = outerFunction();
innerFunction(); // logs 'I am an outer variable'Prototypal Inheritance#
Prototypal inheritance is a way to share methods and properties between objects. In Javascript, each object has a prototype object, which it inherits methods and properties from. Here is an example:
function Person(name) {
this.name = name;
}
Person.prototype.sayHello = function() {
console.log(`Hello, my name is ${this.name}`);
}
const person = new Person('Raju');
person.sayHello(); // logs 'Hello, my name is Raju'Asynchronous Programming#
Asynchronous programming in Javascript allows you to execute code without blocking the main thread. This is essential for building responsive web applications. Here is an example using promises:
function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve('Data fetched successfully');
}, 1000);
});
}
fetchData().then((data) => {
console.log(data);
}); // logs 'Data fetched successfully' after 1 secondGenerators#
Generators are functions that can be paused and resumed. They allow you to write asynchronous code in a synchronous style. Here is an example:
function* generator() {
yield 1;
yield 2;
yield 3;
}
const iterator = generator();
console.log(iterator.next()); // logs { value: 1, done: false }
console.log(iterator.next()); // logs { value: 2, done: false }
console.log(iterator.next()); // logs { value: 3, done: false }
console.log(iterator.next()); // logs { value: undefined, done: true }