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JavaScript JavaScript Loops, Arrays and Objects Simplify Repetitive Tasks with Loops A Closer Look at Loop Conditions

Posted by Nelson Lourenco
Nelson Lourenco
1,766 Points

origin of var guess vs. var randomNumber

I'm having a hard time wrapping my head around the origin of 'var guess' vs 'var randomNumber' For example, the logic reads that:

var randomNumber = getRandomNumber(upper); 

function getRandomNumber(upper) {
  return Math.floor( Math.random() * upper ) + 1;
}

while ( guess !== randomNumber ) {
  guess = getRandomNumber(upper);
  attempts += 1; 
}

So this is how I am reading the above: 

var randomNumber = getRandomNumber(upper) = var guess

By that logic, how does var guess NOT EQUAL to randomNumber every time? I'm confused as to how var guess results in a different number than what results from the getRandomNumber function.

Thanks!

3 Answers

leong shing chew
leong shing chew
5,618 Points
leong shing chew
leong shing chew
5,618 Points

Its true that :

var guess = getRandomNumber(upper);
var randomNumber  = getRandomNumber(upper);

But the one thing to note is that getRandomNumber(upper) returns a "Random" number every time its invoked.

In the code, everytime the following is invoked, guess gets a new "Random" number guess = getRandomNumber(upper);

Nelson Lourenco
Nelson Lourenco
1,766 Points

I understand that the getRandomNumber(upper) results in a new random number every time. I don't quite understand your last sentence however.

leong shing chew
leong shing chew
5,618 Points
leong shing chew
leong shing chew
5,618 Points 
guess = getRandomNumber(upper);

the above at every attempt will return a new number, that part you understand, correct?

As "randomNumber" and "guess" both call the function separately, they both gotten possibly a different number.

In no place the the above code does it specify that 

guess = randomNumber
Nelson Lourenco
Nelson Lourenco
1,766 Points

Aha, thanks for the clarification leong. In my mind, I was thinking that getRandomNumber(upper) was generating the SAME random number in both locations it was called up.

Martin Labik
Martin Labik
5,497 Points
Martin Labik
Martin Labik
5,497 Points

I think they should change this example because this made my brain overheat so hard as well :D Thanks leong ;)

Rick Rana
Rick Rana
10,285 Points
Rick Rana
Rick Rana
10,285 Points

Great question and answer. I was puzzled by this as well. Thanks!