Include issue in JavaScript with arrays

Question

I am having an issue with a simple logic in JavaScript, that checks for digits occurrence in an arrays. The problem is defined as follows:

No match 0

Make certain that your application accommodates repeating digits. For example, if a user guesses 1, 2, and 3, and the randomly generated digits are 1, 1, and 1, do not give the user credit for three correct guesses - just one. Save the file as Lottery.

The main issue is happening at if (lotteryResults.includes(guesses[j])). I don't know why it is working when I hard code a value in the includes.

You said you are having an issue and where it is occurring. But you did not mention what issue you are facing! — Krishna Prashatt
– Krishna Prashatt, Commented Apr 2, 2019 at 11:55
Despite guessing the correct number(s), it is still showing me won zero — crazydev
– crazydev, Commented Apr 2, 2019 at 11:58

Maheer Ali · Accepted Answer · 2019-04-02 12:04:12Z

The problem is that prompt() returns a string that should be converted to number. You can use + to convert it to number

for (var i = 1; i <= TIMES; i++) {
  var userInput = +prompt("Enter a guess");
  guesses.push(userInput);
}

And second problem is that you are comparing arrays guesses == lotteryResults. This will never return true. You can use join() and then compare

if (guesses.join('') == lotteryResults.join(''))

var TIMES = 3;

var userFirstGuess;
var userSecondGuess;
var userThirdGuess;

var guesses = [];

var firstRandom = Math.floor(Math.random() * 3) + 1;
var secondRandom = Math.floor(Math.random() * 3) + 1;
var thirdRandom = Math.floor(Math.random() * 3) + 1;

for (var i = 1; i <= TIMES; i++) {
  var userInput = +prompt("Enter a guess");
  guesses.push(userInput);
}

alert(guesses);

var winTen = 10;
var WinHun = 100;
var winThoun = 1000;
var winMillion = 10000;
var winZero = 0;

var lotteryResults = [];
lotteryResults.push(firstRandom);
lotteryResults.push(secondRandom);
lotteryResults.push(thirdRandom);

if (guesses.join('') == lotteryResults.join('')) {
  alert("You have won: $ " + winMillion);
} else {
  var matchCount = 0;
  for (var j = 0; j < guesses.length; j++) {
    if (lotteryResults.includes(guesses[j])) {
      matchCount++
      var index = lotteryResults.indexOf(guesses[j]);
      lotteryResults.splice(index);
      alert('Lottery ' + lotteryResults);
    }
  }

  switch (matchCount) {
    case 0:
      alert("You have won: $ " + winZero);
      break;
    case 1:
      alert("You have won: $ " + winTen);
      break;
    case 2:
      alert("You have won: $ " + winHun);
      break;
    case 3:
      alert("You have won: $ " + winThoun);
      break;
  }
}

Vladimir Bogomolov · Accepted Answer · 2019-04-02 11:59:56Z

2

Answering your current problem, the prompt writes entries of type string into guesses. And after that you're trying to find a number inside.

What I suggest is to parseInt the guesses[j]

if (lotteryResults.includes(parseInt(guesses[j])) {

Another issue I found is

if (guesses == lotteryResults) {

You can't compare arrays like that. You might try

if (guesses.join('') === lotteryResults.join('')) {

EDIT Example:

console.log([7,3,1] === [7,3,1])
console.log([7,3,1].join('') === [7,3,1].join(''))

edited Apr 2, 2019 at 11:59

answered Apr 2, 2019 at 11:57

Vladimir Bogomolov

1,79414 silver badges20 bronze badges

1 Comment

Maheer Ali Over a year ago

Sorry I was wrong. We can't compare arrays. Thanks for telling +1

Nikita Sharma · Accepted Answer · 2019-04-02 12:05:24Z

1

Here var userInput = prompt("Enter a guess"); console.log(typeof userInput) // returns string. So when you are checking lotteryResults.includes(guesses[j]) it returns false for example lotteryResults.includes("4") // returns false.

You can fix your code as :

var userInput = prompt("Enter a guess"); guesses.push(Number(userInput));

OR

var userInput = prompt("Enter a guess"); guesses.push(parseInt(userInput));

answered Apr 2, 2019 at 12:05

Nikita Sharma

654 bronze badges

Comments

Nemer · Accepted Answer · 2019-04-02 12:18:25Z

0

you have to change the prompt values to Numbers just add + before gusses[j] try my code:

  for (var j = 0; j < guesses.length; j++) {
    if (lotteryResults.includes(+guesses[j])) {
      matchCount++
      var index = lotteryResults.indexOf(+guesses[j]);
      if(index !== -1){
      lotteryResults.splice(index,1);
      }
      alert('Lottery ' + lotteryResults);
    }
  }

answered Apr 2, 2019 at 12:18

Nemer

6871 gold badge6 silver badges11 bronze badges

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