How to generate a random number in Ruby from a specific minimum range to a maximum variable?-CodePudding

How to create a random number generator in Ruby? I know there are ways to do it like rand(0..9) to generate a random number from 0 to 9, or rand(0…9) to generate a random number from 0 to 8. But what if I say rand(0.. *variable*) to generate a random number from 0 to the value of that variable?

Look at the code below for a clearer example:

Suppose I’m creating a number guessing game

print “Enter a number: “
max_num = gets
max_num.to_i #converting it into an integer to print it out with strings

random_num = rand(0.. **max_num**)

CodePudding user response：

max_num.to_i does not change the string to an integer. The string is still a string. The method to_i returns an integer that's not the string.

irb> s = "123"
irb> p s.to_i
123
irb> p s
"123"

What you need to do is to assign the return value to a variable (even the same variable will do) and use that variable, like

max_num = max_num.to_i
random_num = rand(0..max_num)

Actually, in Ruby, though there are lots of methods that can change the internal state of the receiver (like Array#map! and String#strip!), there's no method that can change the type of the receiver.

CodePudding user response：

Use Ruby's sample method.

max = 8
a = [*1..max]
p a.sample

Output