#math.random

[benmillerbct]

note to self: if I need help with java, my dad can help. if I need help with processing though, he can't teach me that.

while processing uses java, the actual java stuff is hidden and compiled by the program for me so i don't have to worry too much.

when a java user writes in processing, without knowing how processing works, they may just write stuff that processing already does for them.

it was kind of funny to see, yet very insightful.

[ngodingkode-blog-blog]

JavaScript Math.random vs. Infinitiy

JavaScript Math.random vs. Infinitiy

Is there any way that this piece of code can return Infinity. We use it in our code to generate a random numbers in the browser but some clients return Infinity.

Math.floor(Math.random() * Math.pow(10, 5))

The only way I can think of is that someone has overwritten Math.random

Answer

View On WordPress

[gliitchesmoved]

+3

[[_”Do you need any water? It’s hot out here.” 

celtle bad-assblonde gogofast

[alisonkinross]

Generating random numbers in Javascript!

This week at HackerYou, we are learning javascript!! I am super excited for it. I have a somewhat reasonable background in programming from my undergrad (mostly in Fortran90 and Matlab), but it's a little rusty. Our first day was nice because it was mostly a review of conditional logic, booleans, and loops. 

I decided to program a rock paper scissors game, which I've included in case anyone wants to walk through it. But I've noticed the most confusing part tends to be the 'random' method on the 'Math' object. So I've decided to focus on explaining that. 

First, I set player1 and player2 to a random number (either 1, 2, or 3) using the code below: 

Math.ceil(Math.random()*3)

Basically, Math.random will give you a random number between 0 and 1. But, we'd like to expand that range so that it goes from 0 to 3. In order to do that, we multiply the random number by 3. Next, since we want to deal with whole numbers, we use Math.ceil on our random number between 0 and 3. Math.ceil works to round every number up to the next whole number - this will give use random numbers that are either 1, 2, or 3. If ever you wanted random whole numbers from 13 to 40 (including 40 but not 13), for example, you would say:

Math.ceil(Math.random()*(40 - 13) + 13)

The best way to test your code is to see what number would be generated if Math.random() is 0, and then test what would happen if it's 1. In the above case, if Math.random() is equal to 0:

Math.ceil(0*(40-13) + 13) = Math.ceil(0 + 13) = Math.ceil(13) = 13 

This would represent the very lowest possible generated number. However, 0 will not likely be generated by Math.random(), so the lowest number will effectively be 14. Now, let's try Math.random() = 1.

Math.ceil(1*(40-13) + 13) = Math.ceil(40 - 13 + 13) = Math.ceil(40) = 40

This represents the highest possible number! You know can be sure that every number will be a whole number between 13 and 40 :) Check out the rock paper scissors game to see how I integrated this method into my game (rock = 1, paper = 2, scissors = 3) with a random number generator!

[kerimaltintop-blog]

Java - Random Kullanımı - Rasgele 0 ile 100 arasında Sayi Üretme

public class RANDOMSINIFI { public static void main(String []args) { for (int i = 0; i < 100; i++) { int sayi = (int)( 1 + Math.random() * 100); System.out.println(sayi); } } }