Random Numbers

Before we continue with the obstacle game, we need to know how to create random numbers in JavaScript. Here is the code required to generate a random number from 1-10.

This code has several parts:

Math.random() - generates a random decimal from 0 to 0.99999, but never 1.

Math.random() * 10 - by multiplying the range by 10, we can now make random numbers from 0 to 9.99999.

Math.random() * 10 + 1 - here, we're just adding 1 to the previous range, so now we have 1 to 10.99999

Math.floor(Math.random() * 10 + 1) - Math.floor() rounds its argument down, so our final range is 1 to 10.

Review Challenges

A. Generate a random number from 1 - 100, and output that number using document.write()

B. Generate a random number from 10 - 20, output the number.

Randomized Block Movement