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JavaScript

Posted by Leonardo Motta
Leonardo Motta
11,284 Points

Problem with my logic lotery numbers.

I need to return an array with 6 random numbers. They need to be from 1 to 60 and all the 6 numbers have to be unique.

this current version just crashes.

function getLoteryGame() {
  var loteryGame = [];
  var usedNumbers = [];
  var randomNumber;

  for (var i = 0; i < 6; i++) {
    randomNumber = Math.floor(Math.random() * 60 + 1);
    usedNumbers[i] = randomNumber;
    if(usedNumbers.includes(randomNumber)) {
      i--;
    } else {
      loteryGame[i] = randomNumber;
    }
  }
  return loteryGame;
}

console.log(getLoteryGame());

4 Answers

Elijah Quesada
.a{fill-rule:evenodd;}techdegree seal-36
Elijah Quesada
Front End Web Development Techdegree Graduate 32,965 Points

This article helped me figure out the sort method for arrays.

https://teamtreehouse.com/community/javascript-sort-method-how-does-the-comparison-actually-work

function getLoteryGame() {
  var loteryGame = [];
  var usedNumbers = [];
  var randomNumber;

  for (var i = 0; i < 6; i++) {
    randomNumber = Math.floor(Math.random() * 60 + 1);
    if(usedNumbers.includes(randomNumber)) {
      i--;
    } else {
      loteryGame[i] = randomNumber;
      usedNumbers[i] = randomNumber;
    }
  }

  loteryGame = loteryGame.sort( function(a,b) {
     return a - b;
  });
  return loteryGame;
}

console.log(getLoteryGame());
Leonardo Motta
Leonardo Motta
11,284 Points

How would it be without arrow function? I couldn't understand that, sorry

Elijah Quesada
.a{fill-rule:evenodd;}techdegree seal-36
Elijah Quesada
Front End Web Development Techdegree Graduate 32,965 Points

Nice job though, on figuring out the duplicate issue. 

loteryGame = loteryGame.sort(function(a,b) {
     return a - b;
  });
  return loteryGame;
}
Leonardo Motta
Leonardo Motta
11,284 Points

Thanks!

Leonardo Motta
Leonardo Motta
11,284 Points

So we can make a function inside another is that it?

Elijah Quesada
.a{fill-rule:evenodd;}techdegree seal-36
Elijah Quesada
Front End Web Development Techdegree Graduate 32,965 Points

Yes, because functions are treated as first class citizens. You can pass them into other functions.

https://teamtreehouse.com/library/callback-functions-in-javascript

Leonardo Motta
Leonardo Motta
11,284 Points

Thanks for the help, was a bit trick because I didn't reach this level yet, But I got this!

Elijah Quesada
.a{fill-rule:evenodd;}techdegree seal-36
Elijah Quesada
Front End Web Development Techdegree Graduate 32,965 Points

No problem. Happy coding!!

Leonardo Motta
Leonardo Motta
11,284 Points
Leonardo Motta
Leonardo Motta
11,284 Points

I got stuck in a infinit loop, that was the problem.

here is the solution:

function getLoteryGame() {
  var loteryGame = [];
  var usedNumbers = [];
  var randomNumber;

  for (var i = 0; i < 6; i++) {
    randomNumber = Math.floor(Math.random() * 60 + 1);
    if(usedNumbers.includes(randomNumber)) {
      i--;
    } else {
      loteryGame[i] = randomNumber;
      usedNumbers[i] = randomNumber;
    }
  }
  return loteryGame;
}

console.log(getLoteryGame());
Leonardo Motta
Leonardo Motta
11,284 Points
Leonardo Motta
Leonardo Motta
11,284 Points

Now that it does what I want how to sort it from the lower number to the highest [1, 2, 3, 4, 5, 6]

return loteryGame.sort(); is not doing it.

Mike Hatch
Mike Hatch
14,941 Points

Using Elijah's workable code you would change 60 to 6 if you want the output to be [1, 2, 3, 4, 5, 6].

Leonardo Motta
Leonardo Motta
11,284 Points
Leonardo Motta
Leonardo Motta
11,284 Points

The final version of my function.

function getLoteryGame() {
  var listToPlay = [];
  var usedNumbers = [];
  var loteryGame;
  var randomNumber;

  for (var i = 0; i < 6; i++) {
    randomNumber = Math.floor(Math.random() * 60 + 1);
    if (usedNumbers.includes(randomNumber)) {
      i--;
    } else {
      listToPlay[i] = randomNumber;
      usedNumbers[i] = randomNumber;
    }
  }

  listToPlay = listToPlay.sort(function(a, b) {
    return a - b;
  });
  return (loteryGame = listToPlay.join(" "));
}

console.log(getLoteryGame());