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JavaScript

Jonathan Grieve
MOD
Jonathan Grieve
Treehouse Moderator 91,254 Points
Posted by Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,254 Points

Quick question on Javascript Conditionals

I remember in the Javascript Basics course David talks about in conditions you have to have one if statement and one else statement.

But in the code for the Random Number challenge which has 2 separate conditions, there are variations.

Is there an exception to this that wen there are else if conditions in a conditional there's no requirement for an else keyword?

var correctGuess = false;
var randomNumber = Math.floor(Math.random() * 6 ) + 1;
var guess = prompt('I am thinking of a number between 1 and 6. What is it?');
**if** (parseInt(guess) === randomNumber ) {
  correctGuess = true;
} else if ( parseInt(guess) < randomNumber ) {
  var guessMore = prompt('Try again. The number I am thinking of is more than ' + guess);
  if (parseInt(guessMore) === randomNumber) {
      correctGuess = true;
  }
} else if ( parseInt(guess) > randomNumber ) {
   var guessLess = prompt('Try again. The number I am thinking of is less than ' + guess);
  if (parseInt(guessLess) === randomNumber) {
      correctGuess = true;
  }
}
**if** ( correctGuess ) {
    document.write('<p>You guessed the number!</p>');
} **else** {
    document.write('<p>Sorry. The number was ' + randomNumber + '.</p>');
}

1 Answer

Vittorio Somaschini
Vittorio Somaschini
33,371 Points

Hello Jonathan.

I do NOT think that the else condition is a must. Actually if you got all the cases covered with if and else if statement/s else would be redundant.

If you have cases that are not covered by you statements already, that it will be surely better to add an else statement at least just to print an error or deal with that particular "else" situation..

Talking about the code you provided the second else if could be an else with no problems according to me, but there should be no problem in leaving it like it is in the example.

Vittorio

Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,254 Points
Jonathan Grieve
Jonathan Grieve
Treehouse Moderator 91,254 Points

I think I misunderstood Dave in his video,

The requirement is if you use an else it has to go at the end, which makes sense. Question answered. :)