Help with a javascript code (Beginner)

Question

They gave me an exercise but when I send it to see if it’s right they tell me it’s wrong, that it’s not returning the correct value. To be more exact they claim that:

- The function summeDe25(10) must return 2.5

moedas = 0
function somarMoedasDe25 (quantidadeDeMoedas){
  for (let i = 0; i < quantidadeDeMoedas; i++){
    moedas = moedas + 0.25
  }
  return moedas
}

But I do tests and when I put 10 as a parameter it returns 2.5

As a beginner, I’m not sure if it’s my code that’s really wrong. Can you help?

Answer 1

I imagine that if you are submitting this code for some automatic test, this test will call your function several times with different parameters.

Like moedas is declared in the global scope, this value will only be incremented as a result of your function calls, see the example:

moedas = 0
function somarMoedasDe25(quantidadeDeMoedas) {
  for (let i = 0; i < quantidadeDeMoedas; i++){
    moedas = moedas + 0.25
  }
  return moedas
}

console.log('O resultado da soma de 5 moedas é:', somarMoedasDe25(5))
console.log('O resultado da soma de 10 moedas é:', somarMoedasDe25(10))

You should probably declare moedas within its function to have no side effects:

function somarMoedasDe25(quantidadeDeMoedas) {
  let moedas = 0
  for (let i = 0; i < quantidadeDeMoedas; i++){
    moedas = moedas + 0.25
  }
  return moedas
}

console.log('O resultado da soma de 5 moedas é:', somarMoedasDe25(5))
console.log('O resultado da soma de 10 moedas é:', somarMoedasDe25(10))

You could also return quantidadeDeMoedas * 0.25 instead of using a for, This is part of the exercise?