Why does my Javascript converter raise a ReferenceError?-CodePudding

I developed this python app to convert turkish gold coins to ounce price for the carefull consumer. However, to publish to the web, it's required to convert it to javascript. The problem is that it raises an error:

ReferenceError: q is not defined.

Why does it raise this error and how can I fix it?

// Print the welcome message
console.log('||| Welcome to our app which shows the ounce prices and optimum prices of homeland gold coins.||| \n||| Use the numbers for type of gold coins below ||| \n||| Cumhuriyet(1),Tam(2),Yarım(3),Çeyrek(4),Finish the calc and show sum(5) ||| ');
console.log('||| This is a calc which calculates the entries you have entered by order.||| \n||| To quit enter the type of gold 5 and amount of gold is any number. |||');

// Collect data from web
async function getData() {
  const url = 'https://yorum.altin.in/tum/ons';
  const headers = {
    'User_Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.88 Safari/537.36'
  };
  const page = await fetch(url, {
    headers
  });
  const content = new DOMParser().parseFromString(await page.text(), 'text/html');
  const x = content.getElementById('ofiy').innerText.trim();
  const y = content.getElementById('dfiy').innerText.trim();
  const a = parseFloat(x.substring(1, 9));
  const c = parseFloat(y.substring(0, 6));
  const ws = [0.212666471635951 * a * c, 0.206772168098369 * a * c, 0.103386084049185 * a * c, 0.0516930420245924 * a * c];
  const calcx = [];
}

// Define the main loop
async function main() {
  let q = parseInt(prompt('enter representive number of your coin: '));
  let wx = parseInt(prompt('enter amount of gold which related to q value: '));
}

// Define the function that calculates the price of the gold coins
function pr_gold() {
  if (q === 1) {
    calcx.push(ws[0] * parseInt(wx));
  } else if (q === 2) {
    calcx.push(ws[1] * parseInt(wx));
  } else if (q === 3) {
    calcx.push(ws[2] * parseInt(wx));
  } else if (q === 4) {
    calcx.push(ws[3] * parseInt(wx));
  } else if (q === 5) {
    console.log(`||| Calculation is completed. USD/TRY parity is ${c} TRY and ounce price of gold is ${a} USD |||`);
    console.log(`||| The total value of your Turkish gold coins are ${Math.ceil(calcx.reduce((a, b) => a   b, 0))} TRY |||`);
  } else {
    console.log("Invalid input. Please enter a number between 1 and 5.");
  }
}

pr_gold();

CodePudding user response：

So you said your app is in python, and you are trying to publish it to the web, you don't have to convert your code to Javascript, you can create a WebApp/WebApi application, it is like making a website, but all the website will do is the conversion, everything else remains in python, I will suggest you go the web API route, that will be simpler, Python Has A FastAPI (

So the above code works for the input q=2 and wx=2 other inputs might give you an error, but I am still debugging it. let me know if you are interested in the refined code that works for all scenarios. The following inputs q=5 and wx=2 will give you an error, just saying before you think my code does not work, I fixed the code to work on the bare minimum.

Yeah, So I Got A CORS Error, if you run my code and also get the CORS error, visit this site https://cors-anywhere.herokuapp.com/corsdemo there will be a button that says "request temporary access to demo server" click it then rerun the code.

Due to the fact that you made your functions async, I had to use the ".then()" notation to get this to work, I would suggest you learn about async stuff, anyone reading this should please link to some async materials. It's good to use async but first make sure you need it, I feel like I can write this code in a more beginner-friendly manner without async.

Looking at the code, it looks like whoever wrote it hasn't yet grasped the workings of variable scopes, the user @jabaa https://stackoverflow.com/users/16540390/jabaa posted a link to materials on JS async stuff, I will just post it here for convenience

Does this answer your question?https://stackoverflow.com/questions/500431/what-is-the-scope-of-variables-in-javascript

Yeah, So any further questions, post below, looking at the code, I feel like whoever wrote this code needs 1 or 2 weeks more of tutorials into the Javascript Basics.

I did not explain much of the changes I did, because well, it will be like I am writing documentation, and that's not my favorite thing to do, so post in the comment below as to whether I should explain my changes, then I will do it ( i will only do that if the request comes from @lex ).

CodePudding user response：

q and wx are not being defined before they are used in the main function. Do this:

let q;
let wx;

Then assign them a value using prompt function:

q = parseInt(prompt('enter representive number of your coin: '));
wx = parseInt(prompt('enter amount of gold which related to q value: '));