Javascript Practice 36: JS Hero - Random numbers

 

Question: 

Write a function dice that returns like a dice a random number between 1 and 6.

Answer: 

function dice () {

return (Math.floor(Math.random() * 6)) + 1;

}; 

> function dice has to return a random number between 1 and 6 

> random numbers can be generated using the Math.random method

> Math.random returns a floating-point, pseudo-random number

> random number is usually between 0 (inclusive) and 1 (exclusive)

> let me repeat - random number generated will be between 0 & 1

> 0 will be inclusive & 1 will be exclusive

> 0 will be included and 1 will not be included 

> we shall be generating numbers with decimal points (real numbers) and not a whole number

> for eg 0.75 or 0.89 or 0.9998898988898552 etc

> but we need to get a random whole number between two values i.e. 1 and 6 

> so first we need to use Math.random() to generate a number between 0 & 1

> we then multiply that with 6 like this: (Math.random() * 6)

> (Math.random() * 6) will generate random real numbers (not whole numbers) btw 0 & 6

> 0 will be included and 6 will not be included

> for eg 0.256, 1.536, 3.589 or 5.99958565

> then we wrap the result of (Math.random()*6) inside the Math.floor function to round it 

> like this: Math.floor(Math.random() * 6)

> Math.floor will round the number down to the closest whole number 

> this will generate whole numbers from 0 to 5 

> in order to ensure that our random numbers fall between 1 and 6 we simply add 1 

> like this: (Math.floor(Math.random()*6)) + 1; 

> the resulting numbers will always be between 1 and 6