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ch 4 - declaring functions

Posted: Tue Sep 18, 2018 6:40 pm
by DanceFourFun
In the DIY for chapter 4 -

I don't understand enough about what went on in the chapter to be able to implement it in the DIY, even after the follow along and looking at the answer. Can you give some guidance or assistance? Thank you.

Re: ch 4 - declaring functions

Posted: Tue Sep 18, 2018 9:20 pm
by JeremyMoritz
I am happy to assist. Can you please be a more specific about what it is that you're asking? Is there a line in particular that you find confusing? Also, approximately how old are you (this helps me to tailor my answer toward your age range)?

To get you started, answer this question: Can you create a function that will generate a random number every time you call it?

For instance, do you know how to complete this code?

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function getRandomNumberBetweenOneAndHundred() {
    // do you know what to `return` here to make this function work?
}

getRandomNumberBetweenOneAndHundred();  // this should return the value you want after you've finished working out the function above

Re: ch 4 - declaring functions

Posted: Wed Sep 19, 2018 4:39 pm
by dancefourfun
I am 14 years old. I don't understand most of declaring functions. I was following along in the book really well until this chapter. I understand what to type once I have read the code from the book once or twice, but without something to look at, I don't know how to type it. I also don't know what to type to create the code you were asking about, or complete the other code, without something to copy.

I can create a random number between 0 and 1 by myself, but I don't understand how to put that in a function. I also don't understand the Math.floor even by itself, the console.log, and nesting functions.

Re: ch 4 - declaring functions

Posted: Wed Sep 19, 2018 10:31 pm
by JeremyMoritz
If you can create a random number between zero and one, start with that. If you multiply that number by 100, you'll end up with a random number between z and 100:

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let randNumZeroToOne = Math.random();
let randNumZeroToHundred = randNumZeroToOne * 100;
console.log(randNumZeroToHundred);
Notice that this number has lots of digits after the decimal point. You use Math.floor() to strip away all those digits (rounding your number down to the floor):

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let newRandNum = Math.floor(randNumZeroToHundred);
Then, you need to RETURN this number inside the function:

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return newRandNum;
Put all that code inside of the function (between the { and the } ). Then whenever you need one of the numbers, just call that function

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getRandomNumberBetweenOneAndHundred();


If you're still having trouble, try doing a google search for "What is..." Math.random(), Math.floor(), console.log(), etc. You'll probably find many clear examples about how to use each one.

Hope this helps!

Oh and one more thing: after doing the google search, if you're still struggling with this concept, go ahead and try out the next chapter. Sometimes it takes seeing new examples to understand some of the foundational concepts. There's no shame in not getting it right away. If you can read code enough to understood the book well up until this chapter, then you've already got a big headstart over most 14 year olds (most don't know the first thing about coding). So don't be too hard on yourself. You'll be able to figure it out.

Re: ch 4 - declaring functions

Posted: Thu Sep 20, 2018 3:15 am
by dancefourfun
Thank you so much! I think it will really help me. I appreciate you answering my questions.