DEV Community: hacker4world

Share with me your python automation ideas for your computer

hacker4world — Thu, 11 Aug 2022 22:42:56 +0000

Im building an assistant for my pc using python that mainly does automate boring things on my computer.

However im finding it difficult to find automation ideas to add to the software so please do share with me some ideas on what to automate.

Add custom methods to Javascript built-in classes

hacker4world — Wed, 25 May 2022 18:15:52 +0000

Some people do not know this but you can actually add your own custom methods to strings, arrays and much more

Prototypes

As we know, every class in Javascript has a prototype containing all the methods that the instances of that class can use and we can access it using Class.prototype.

Adding methods to a prototype

Let's create a method called reverse to the String prototype that reverses the string:

String.prototype.reverse = function() {
    let rev = "";
    for (let i = 0; i < this.length; i++) {
        rev = this[i] + rev;
    }
    return rev;
}

Now that will do the trick.
so the thing is that prototypes are also objects, and objects can have methods, so we attached the method reverse to the string prototype object, the this keyword inside the method will refer to the string we calling the method on.
now to use it we simply call it like any other method

console.log("Hello".reverse()); //olleH

Now i don't know how would this be useful but i thought it's a cool thing to know!

What tools do you use to improve your productivity ?

hacker4world — Tue, 17 May 2022 09:47:29 +0000

There are countless of tools that makes working as a developer easier lile editor extensions, apps and browser extensions
Share with me what tools do you use

The importance of sharing knowledge

hacker4world — Mon, 09 May 2022 20:00:32 +0000

I discovered that i have a weird and strong passion to share the knowledge about programming i have with friends who are programmers like me or even an unknown person who needs that knowledge, and all i have to say is that it is good and valuable to share atleast some of what you know and here is how.

The benefit of sharing knowledge

when you share knowledge about coding, it can solidify that knowledge even more because teaching something is a great way to learn it even more, also it is so valuable to the person you teaching it to so it's a win win situation and it can improve your skills at teaching.

Ways of sharing knowledge

programming knowledge can be shared by making tutorials, writing books, creating courses even explaining a single thing is a form of sharing.

so the point of this post is to encourage people who have some skills not only in programming but in anything to atleast try and share some of it for your personal benefit and for the benefit of whoever teaching it to.

What projects are you currently working on ?

hacker4world — Sun, 08 May 2022 18:21:03 +0000

As developers, we create simple and complex projects maybe for a job, sell them or just for practicing what you learn, what projects did you build or currently building ? i'd love to know what creative things you built
and if it's open source feel free to share your project public repo

Should you know everything to land a job as a developer ?

hacker4world — Sun, 08 May 2022 15:22:28 +0000

I see a lot of people who are still learning programming think that in order to land a good job as a developer you need to know every technologie and every programming language involved with that type of programming you do.
And the reality is that no it's not necessary to know everything in order to get a job because nobody knows everything there is to know and the best of us starts as a junior developer then start improving over time, but the most importing thing you should have as a developer is the constant will to learn new stuff all the time and that what makes you better everyday so in my opinion that's something you need to have.
Tell me what do you think about this

What do you do to stay motivated while learning ?

hacker4world — Sat, 07 May 2022 19:08:56 +0000

Learning to program can be hard and overwhelming, what do you do to keep motivating yourself in the long run ?

Nestjs: Introduction and setup

hacker4world — Sat, 07 May 2022 15:46:25 +0000

Nestjs is a Nodejs framework to build complex backend applications using Typescript instead of javascript for better code reliablity and less bugs.

Why use Nestjs

So why should you use Nestjs instead of just using express ? the answer is that Nestjs is kinda more opinionated on how you structure your application code, meanwhile express let's you freely organize the app howerver you want and that may lead to bad structure especially when your application grows in size and complexity, also Nestjs provides support for database connection, authentication, caching, graphql, testing and many other things out of the box.
also, keep in mind that Nestjs uses express behind the scenes but you can change it to fastify which is another good nodejs framework, so why not put the time to learn Nestjs ?

How a Nestjs app is structured

Nestjs applications are divided into modules, each module takes care of 1 feature of that application.
let's take an Ecommerce app as an example and divide it to Nests modules it would look something like this:

and each module contains:

a controller where you define the different routes for that feature
a service that contains all the business logic related to that feature
guards to prevent access for a certain route until a condition is met (authentication for example)
a repository to access the database
data transfer objects to ensure the data coming from the client is valid
pipes to transform data

Getting started with Nestjs

First you need install Nodejs on your sistem, then install the Nestjs cli globally

npm install -g @nestjs/cli

then create a new project

nest new project-name

now you can open your editor and start coding the app

What technologies are you currently learning ?

hacker4world — Fri, 06 May 2022 19:53:52 +0000

There is countless tools, frameworks, and languages available out there, share with me what are you currently learning or what you wanna learn in the future i'd love to know what the community has to learn

Javascript scope and scope chain

hacker4world — Fri, 06 May 2022 11:19:24 +0000

A scope is like a place where we can access a certain declared variable in Javascript, when the variable is not availabe in a certain scope it cannot be used there.

Types of scopes

there are 3 main types of scopes found in Javascript

The global scope

This is the scope where you can access any declared variable or function and it is on the top level

const name = "John";
console.log(name); // John

the variable name is created in the global scope so it is accessible everywhere even inside a function scope

const name = "John";
function logName() {
    console.log(name); //John
}
logName();

The function scope

This is the scope inside functions and methods and anything declared there cannot be accessed in the global scope

function createName() {
    const name = "John";
    console.log(name); // John
}
createName();
console.log(name); // name is not defined

The block scope (ES6 only)

This is the scope inside if statements and loops, any variable declared there with let and const cannot be accessed outside the scope

if (true) {
    const name = "John";
}
console.log(name); // name is not defined

however, if we declare the variable with var, it can be accessed outside the scope

if (true) {
    var name = "John";
}
console.log(name); // John

The scope chain

If we make a scope inside a scope inside another scope we make a scope chain

Example

function fnc1() {
  //scope 2
  return function () {
    //scope 3
    return function () {
      //scope 4
      return function () {
        //scope 5
      };
    };
  };
}

and every scope only has access to variables declared inside a higher level scope.
scope 5 has access to all scope 4, 3, 2 and global scope variables
scope 4 has access to all scope 3, 2, and global scope variables
etc

High order functions in Javascript

hacker4world — Thu, 05 May 2022 13:03:35 +0000

High order functions are functions that take another function as a paramater or return another function.
You see in javascript functions can be treated as variables as well so it makes it possible to return them or pass them as params.

Implementing a high order function

Let's implement a simple high order function that takes another function and call it inside it's body

function doSomething(action) {
    action(); // Hi
}

function actionFunction() {
    console.log("Hi");
}

doSomething(actionFunction);

we called the doSomething function and gave it the function actionFunction as param and it simply called it inside it's body and that's perfectly fine in javascript

let's create anothet high order function but now we will instead return a function from it

function getAction() {
  return function() {
    console.log("Hi");
  }
}

const action = getAction();

action(); // hi

we stored the function returned by getAction then called it afterwards to log hi to the console

Existing high order functions in Javascript

javascript has a lot of high order functions built in the language, now let's see some of them that are array methods

the forEach method

let arr = [1, 2, 3, 4, 5];

function log(x) {
  console.log(x); // 1, 2, 3, 4, 5
}

arr.forEach(log);

the forEach function loops through the array and each time it calls the passed function and give it the element currently iterating on

the map function

let arr = [1, 2, 3, 4, 5];

function double(x) {
  return x * 2;
}

const newArr = arr.map(double);

console.log(newArr); // [ 2, 4, 6, 8, 10 ]

the map method replaces the value that is currently iterating on with the value that the passed function returns and then returns the new array

the filter method

let arr = [1, 2, 3, 4, 5];

function isPair(x) {
  return x % 2 == 0;
}

const pairs = arr.filter(isPair);

console.log(pairs); // [ 2, 4 ]

the filter method will only keep array elements that are passed to the function and returns true

Hoisting in Javascript

hacker4world — Wed, 04 May 2022 23:10:58 +0000

In javascript, hoisted objects are objects that can be accessed before their declaration in the code without javascript throwing an error complaining about it.
some things can be hoisted like variables, functions and classes

Variables declared with var

if we try to access a variable declared with var before it's declaration in the code it's value will be undefined

console.log(name); //undefined
var name = "John";

again javascript will set that variable to undefined instead of throwing an error

Variables declared with let and const

these variables are not hoisted and will cause an error if accessed before declaration

console.log(name); //reference error: name is not defined
const name = "John";

Functions

functions are also hoisted and their value will be the function itself which means it can be used perfectly before declaration

sayHi(); //Hi
function sayHi() {
   console.log("Hi");
}

However arrow functions are not hoisted even when declared with var

sayHi(); // sayHi is not a function
var sayHi = () => console.log("Hi");

ES6 Classes

classes are not hoisted and will cause an error when accessed before declared

const person = new Person(); //cannot access 'Person' before initialization

class Person {
  constructor() {}
}

Summary

var variables: hoisted and undefined by default
const variables: not hoisted
functions: hoisted and can be used
arrow functions: not hoisted
classes: not hoisted