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Welcome to Javascript

Node.js is an open source environment for Javascript.

And now that I've concluded the basics with Python, let's keep the ball rolling. I find that, even though Javascript looks a lot more complicated, I gel with it a bit easier, and I'm not sure why.

This is around the first 35 minutes of this tutorial here. I'm going to work through this and find some other resources. I've already found said resources and they look a little different in the code department than this, but it's mostly the same.

We make three things here;



  • Introduce ourselves
  • Make a small game
  • Establish classes and events





A node module is a javascript file.

My initial is appin.js, tutorial file is tut.js. You may want to open and follow along!

Javascript Separates your commands in a way instead of shoving them all into one file by calling to other files that are in the same path (./) and using const tut = require(‘./tut’)



I export classes and PI; It looks a bit ugly like this.

module.exports.PI = PI;
module.exports.Mathing = Mathing;

But we can also do it like this;

module.exports = {sum : sum, PI : PI, Mathing : Mathing}

Events module and events emitter

Event Emitters are what happens when an action - passing a control - takes place

Person is a class, and we put Mori and Hanlon in that class as two seperate objects. I modify the introduction for each name.

let Mori = new Person('Mori');
//Person extends eventemitter class
// Mori is an instance of the event emitter class
Mori.on('name',()=>{
console.log('Name is ' + Mori.name);
})
let Hanlon = new Person('Hanlon');
//Person extends eventemitter class
// Hanlon is an instance of the event emitter class
Hanlon.on('name',()=>{
console.log('And I am ' + Hanlon.name);


Finally, our little game. Variables num3 and num4 (I used num1 and num2 in tut.js, which appin.js pulled) are assigned a random number between 1 and 10 to add.

Q: How can we make the modifier random also?

else{
rl.setPrompt('No try again\n');
//the little new line bugger tripped me up
rl.prompt();
rl.on('line',(userInput)=>{ //this input will be tested
if(userInput.trim() == answer)
rl.close();
else {
rl.setPrompt(`${ userInput } is wrong \n
Try again. You can do it!\n`)
rl.prompt();
}
//it's a loop
})

Line 81 (See GitHub) says "This user input will be tested", so that random strings aren't seen as correct as opposed to the right answer.

If the user gets the question wrong, it loops until they get it correct ('answer'), then it stops the program, returning to the prompt.



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