Problem when trying to show the result of an operation with the elements of an array since it return-CodePudding

This code tries to perform a currency converter, and returns a NaN every time the result is displayed in the alert... however, to try to solve the problem:

I tried to remove the "currencies" constant from the do...while loop, thinking that the values within it would have to be globally available, but it kept giving the same error.
Then it was thought that maybe the objects inside the variable were being accessed wrong and tried using the brackets and the position inside the array but that didn't work either (or maybe it wasn't done correctly).
I also opted to parse with Number() and it didn't work either.

So far it was possible to try but I am almost sure that the problem is there, that the objects inside the array are being accessed incorrectly and that is what you want to know.

do {
    const currencies = [{result: 0}, 
        {dolar: 129},
        {euro: 132},
        {franco: 133},
        {real: 23},
        {yuan: 19}];

     pesos = prompt("Enter pesos to convert");
     currency = prompt("Enter a currency");
    
     function divide (pesos, currency) {
        if (pesos > 0 && currency == "dolar") {
            currencies.result = pesos / currencies.dolar;
            alert(pesos   " pesos are $"   currencies.result.toFixed(2)    " dolars");
            exit = prompt("to continue press ENTER | if you want to exit type EXIT");
            return
        }
        if (pesos > 0 && currency == "euro") {
            currencies.result = pesos / currencies.euro;
            alert(pesos   " pesos are €"   currencies.result.toFixed(2)    " euros");
            exit = prompt("to continue press ENTER | if you want to exit type EXIT");
            return
        } 
        if (pesos > 0 && currency == "franco") {
            currencies.result = pesos / currencies.franco;
            alert(pesos   " pesos are "   currencies.result.toFixed(2)    " francos");
            exit = prompt("to continue press ENTER | if you want to exit type EXIT");
            return
        } 
        if (pesos > 0 && currency == "real") {
            currencies.result = pesos / currencies.real;
            alert(pesos   " pesos are "   currencies.result.toFixed(2)    " reales");
            exit = prompt("to continue press ENTER | if you want to exit type EXIT");
            return
        } 
        if (pesos > 0 && currency == "yuan") {
            currencies.result = pesos / currencies.yuan;
            alert(pesos   " pesos are "   currencies.result.toFixed(2)    " yuanes");
            exit = prompt("to continue press ENTER | if you want to exit type EXIT");
            return
        } 
        else {
            alert("You must enter a value and a currency");
        }
    }
     divide(pesos, currency)
    
} while (exit != "EXIT");

CodePudding user response：

You need to have all currencies and result in a single object, not in an array of objects.

For smaller code, without repetition, you could add in the object the currency sign and name for plurals (not implemented).

function divide(pesos, currency) {
  if (!(currency in currencies) || pesos <= 0) {
    alert("You must enter a value and a currency");
    return;
  }

  currencies.result = pesos / currencies[currency];
  alert(pesos   " pesos are "   currencies.result.toFixed(2)   " "   currency   "s");
  return prompt("to continue press ENTER | if you want to exit type EXIT");
}

const currencies = {
  result: 0,
  dolar: 129,
  euro: 132,
  franco: 133,
  real: 23,
  yuan: 19,
};

let pesos, currency;

do {      
    pesos =  prompt("Enter pesos to convert"),
    currency = prompt("Enter a currency");
} while (divide(pesos, currency) != "EXIT");

CodePudding user response：

Modify your object like this

const currencies = {
result: 0,
dolar: 129,
euro: 132,
franco: 133,
real: 23,
yuan: 19,

};