I have this loop:
puts "Welcome to the Loop Practice Problems"
puts " Write a number between 1 and 10, but not 5 or else...."
ans = gets.chomp!
if ans < 1
puts "Tf bruh bruh"
elsif ans > 10
puts "Now you just playin"
elsif x == 5
print "You wildin B"
else
puts "Fosho that's all I require"
end
It doesn't run properly, and I'm trying to understand why. If you can help me with this, I'd appreciate it.
If you know a good site for practice problems, I'd love to try it. I checked out Coderbyte and Code Kata, but the way they're set up doesn't look right, and they don't have questions to solve for fundamentals.
The issue here is that you're not converting ans to a number, but you're comparing it to one. ans is going to be a string.
In Ruby, when you compare a number to a string, Ruby says that the two aren't equal:
"1" == 1
=> false
You can reproduce the problem with this code:
puts "Welcome to the Loop Practice Problems"
puts " Write a number between 1 and 10, but not 5 or else...."
ans=gets.chomp!
p ans
The p method will output an "inspected" version of that object, (it's the same as doing puts ans.inspect). This will show it wrapped in quotes, which indicates that it's a string.
You probably want to do this:
ans = gets.chomp!.to_i
The to_i method here will convert the number to an integer, and then your comparisons will work correctly.
You have to convert input string type object into integer type
ans = gets.chomp!.to_i #input string convert into integer.
if ans < 1
puts "Tf bruh bruh"
elsif ans > 10
puts "Now you just playin"
elsif x == 5
print "You wildin B"
else
puts "Fosho that's all I require"
end
Related
I wrote a simple guess the number game. But it keeps looping even when I input the correct number. Please help, thanks!
puts "Pick a number between 0 - 1000."
user_guess = gets.chomp.to_i
my_num = rand(831)
guess_count = 0
until user_guess == my_num do
if user_guess == my_num
guess_count += 1
puts "you got it!"
elsif user_guess <= 830
guess_count += 1
puts "higher"
else user_guess >= 1000
guess_count += 1
puts "lower"
end
end
puts "You guessed my number in #{guess_count} attempts. Not bad"
The part of the code that asks for a number from the user is outside the loop, so it will not repeat after the answer is checked. If you want to ask the user to guess again when their guess is wrong, that code needs to be inside the loop.
my_num = rand(831)
guess_count = 0
keep_going = true
while keep_going do
puts "Pick a number between 0 - 1000."
user_guess = gets.chomp.to_i
if user_guess == my_num
guess_count += 1
puts "you got it!"
keep_going = false
elsif user_guess <= 830
guess_count += 1
puts "higher"
else user_guess >= 1000
guess_count += 1
puts "lower"
end
end
puts "You guessed my number in #{guess_count} attempts. Not bad"
This code still has some bugs in it that stops the game from working correctly though, see if you can spot what they are.
As #Tobias has answered your question I would like to take some time to suggest how you might make your code more Ruby-like.
Firstly, while you could use a while or until loop, I suggest you rely mainly on the method Kernel#loop for most loops you will write. This simply causes looping to continue within loop's block until the keyword break is encountered1. It is much like while true or until false (commonly used in some languages) but I think it reads better. More importantly, the use of loop protects computations within its block from prying eyes. (See the section Other considerations below for an example of this point.)
You can also exit loop's block by executing return or exit, but normally you will use break.
My second main suggestion is that for this type of problem you use a case statement rather than an if/elsif/else/end construct. Let's first do that using ranges.
Use a case statement with ranges
my_num = rand(831)
guess_count = 0
loop do
print "Pick a number between 0 and 830: "
guess_count += 1
case gets.chomp.to_i
when my_num
puts "you got it!"
break
when 0..my_num-1
puts "higher"
else
puts "lower"
end
end
There are a few things to note here.
I used print rather than puts so the user will enter their response on on the same line as the prompt.
guess_count is incremented regardless of the user's response so that can be done before the case statement is executed.
there is no need to assign the user's response (gets.chomp.to_i) to a variable.
case statements compare values with the appropriate case equality method ===.
With regard to the last point, here we are comparing an integer (gets.chomp.to_i) with another integer (my_num) and with a range (0..my_num-1). In the first instance, Integer#=== is used, which is equivalent to Integer#==. For ranges the method Range#=== is used.
Suppose, for example, that my_num = 100 and gets.chomp.to_i #=> 50 The case statement then reads as follows.
case 50
when 100
puts "you got it!"
break
when 0..99
puts "higher"
else
puts "lower"
end
Here we find that 100 == 50 #=> false and (0..99) === 50 #=> true, so puts "higher" is displayed. (0..99) === 50 returns true because the integer (on the right of ===) is covered by the range (on the left). That is not the same as 50 === (0..90), which loosely reads, "(0..99) is a member of 50", so false is returned.
Here are a couple more examples of how case statements can be used to advantage because of their reliance on the triple equality method.
case obj
when Integer
obj + 10
when String
obj.upcase
when Array
obj.reverse
...
end
case str
when /\A#/
puts "A comment"
when /\blaunch missiles\b/
big_red_button.push
...
end
Use a case statement with the spaceship operator <=>
The spaceship operator is used by Ruby's Array#sort and Enumerable#sort methods, but has other uses, as in case statements. Here we can use Integer#<=> to compare two integers.
my_num = rand(831)
guess_count = 0
loop do
print "Pick a number between 0 and 830: "
case gets.chomp.to_i <=> my_num
when 0
puts "you got it!"
break
when -1
puts "higher"
else # 1
puts "lower"
end
end
In other applications the spaceship operator might be used to compare strings (String#<=>), arrays (Array#<=>), Date objects (Date#<=>) and so on.
Use a hash
Hashes can often be used as an alternative to case statements. Here we could write the following.
response = { -1=>"higher", 0=>"you got it!", 1=>"lower" }
my_num = rand(831)
guess_count = 0
loop do
print "Pick a number between 0 and 830: "
guess = gets.chomp.to_i
puts response[guess <=> my_num]
break if guess == my_num
end
Here we need the value of gets.chomp.to_i twice, so I've saved it to a variable.
Other considerations
Suppose we write the following:
i = 0
while i < 5
i += 1
j = i
end
j #=> 5
j following the loop is found to equal 5.
If we instead use loop:
i = 0
loop do
i += 1
j = i
break if i == 5
end
j #=> NameError (undefined local variable or method 'j')
Although while and loop both have access to i, but loop confines the values of local variables created in its block to the block. That's because blocks create a new scope, which is good coding practice. while and until do not use blocks. We generally don't want code following the loop to have access to local variables created within the loop, which is one reason for favouring loop over while and until.
Lastly, the keyword break can also be used with an argument whose value is returned by loop. For example:
def m
i = 0
loop do
i += 1
break 5*i if i == 10
end
end
m #=> 50
or
i = 0
n = loop do
i += 1
break 5*i if i == 10
end
n #=> 50
1. If you examine the doc for Kernel#loop you will see that executing break from within loop's block is equivalent to raising a StopIteration exception.
I created a guessing game through Ruby and I believe the structure of my code is off. When entering 'Cheat', you are given the random number then asked to type it in again. When typed in again, it says the random number is not correct and always defaults to my 'elseif' in line 45.
puts "Hey! I'm Sam. What's your name?"
name = gets
puts "Welcome #{name}. Thanks for playing the guessing game.
I've chosen a number between 1-100.
You'll have 10 tries to guess the correct number.
You'll also recieve a hint when you're guess is wrong.
If you feel like being a big ol cheater, type 'Cheat'.
Let's get started..."
random_number = rand(1...100)
Cheat = random_number
counter = 10
loop do
break if counter == 0
divisor = rand(2...10)
guess = gets.chomp
break if guess.to_i == random_number
counter -= 1
if
guess == random_number
puts 'You guessed the right number! You win!'
end
if counter < 4
puts "You can go ahead and cheat by typing 'Cheat'..."
end
if guess.to_s.downcase.eql? "cheat"
puts "The random number is #{random_number} you CHEATER!! Go ahead and type it in..."
guess = gets.chomp
puts = "You win cheater!"
end
if
guess.to_i < random_number
puts 'Ah shucks, guess again!'
guess = gets.chomp
elsif
guess.to_i > random_number
puts 'Too high, guess again!'
guess = gets.chomp
end
if random_number % divisor == 0
puts "Thats not it.\n #{guess} is #{guess.to_i > random_number ? 'less' : 'greater'} than the random number.
The random number is divisible by #{divisor}.\nTry again: "
elsif
puts "That's not the random number.\n #{guess} is #{guess.to_i > random_number ? 'less' : 'greater'} than the random number.
The random number is NOT divisible by #{divisor}.\nTry again: "
end
end
if counter > 0
puts "The number is #{random_number}! You win!"
else
puts "You lose! Better luck another time."
end
this is the response i get in the terminal
Let's get started...
Cheat
The random number is 96 you CHEATER!! Go ahead and type it in...
96
Thats not it.
96 is greater than the random number.
The random number is divisible by 8.
Try again:
The problem is here:
puts = "You win cheater!"
You're assigning the string "You win cheater!" to a local variable named puts. Changing it to this fixes the problem:
puts "You win cheater!"
You'll probably also want to put a break after that line.
As an aside, this pattern:
loop do
break if counter == 0
# ...
end
...would be better expressed as:
while counter > 0
# ...
end
...or:
until counter == 0
# ...
end
Also, you should always put the condition for an if/elsif/whathaveyou on the same line as if et al. Why? Because if you don't you get bugs like this:
if random_number % divisor == 0
# ...
elsif
puts "..."
end
Can you spot the bug? You forgot to put a condition after elsif, or used elsif when you meant to use else, which means that the return value of puts (which is always nil) is being used as the condition, just as if you had written elsif puts "...".
If you make a habit of always putting the condition on the same line as if/elsif, your eye will get used to it and errors like this will jump out at you.
After running this program, it only ever returns "miss"
What have I done wrong?
def method
print "Enter number from 0 to 4"
x = gets.chomp
num = rand(5)
if x == num
puts "hit"
else
puts "miss"
end
end
while 1==1
method
end
thanks
gets.chomp results in a String. Comparing a String to a number with equality will never be true, because they are completely different types.
You should convert x to an integer before comparison, using String#to_i:
x = gets.chomp.to_i
Also, while 1==1 is a bit strange. This is more readable:
while true
method
end
Or even better:
loop { method }
You are reading a string from $stdin:
Change
x = gets.chomp
to
x = gets.chomp.to_i
Hope this helps
Reference
String#to_i
I'm new to Ruby and am currently working on some practice code which looks like the following:
puts 'Hello there, Can you tell me your favourite number?'
num = gets.chomp
puts 'Your favourite number is ' + num + '?'
puts 'Well its not bad but ' + num * 10 + ' is literally 10 times better!'
This code however just puts ten copies of the num variable and doesn't actually multiply the number so I assume I need to make the 'num' variable an integer? I've had no success with this so can anyone show me where I'm going wrong please?
If you are using to_i, then chomp before that is redundant. So you can do:
puts 'Hello there, Can you tell me your favourite number?'
num = gets.to_i
puts 'Your favourite number is ' + num.to_s + '?'
puts 'Well its not bad but ' + (num * 10).to_s + ' is literally 10 times better!'
But generally, using "#{}" is better since you do not have to care about to_s, and it runs faster, and is easier to see. The method String#+ is particularly very slow.
puts 'Hello there, Can you tell me your favourite number?'
num = gets.to_i
puts "Your favourite number is #{num}?"
puts "Well its not bad but #{num * 10} is literally 10 times better!"
Use the to_i method to convert it to an integer. In other words, change this:
num = gets.chomp
To this:
num = gets.chomp.to_i
you can also make sure the number that the user is using is an integer this way:
num = Integer(gets.chomp)
but you have to create a way to catch the error in case the user input otherwise like a char, or string so; it is must better to use:
num = gets.chomp.to_i
In case the user put another type of data, num will be equal to 0 like you can see in this test example:
puts "give me a number:"
num = gets.chomp.to_i
if num >3
puts "#{num} es mayor a 3 "
else
puts "#{num} es menor a 3 o 3"
end
This a example of the interaction with that script:
give me a number:
sggd
0 es menor a 3 o 3
nil
I hope this clarify better your point.
I wrote a similar program as yours. Here is how I finally got it to work properly! I had to assign the favorite number to be an integer. Then, in the next line I set the new_fav_num with the value of fav_num +1 and then converted it to string. After that, you can just plug your code into the return statement that you want to say to the user, only you have to convert the first fav_num to a string.
puts "What is your favorite number?"
fav_num = gets.chomp.to_i
new_fav_num = (fav_num + 1).to_s
puts "Your favorite number is " + fav_num.to_s + ". That's not bad, but " +
new_fav_num + " is bigger and better!"
Hope this helps.
I'm messing around in Ruby some more. I have a file containing a class with two methods and the following code:
if __FILE__ == $0
seq = NumericSequence.new
puts "\n1. Fibonacci Sequence"
puts "\n2. Pascal\'s Triangle"
puts "\nEnter your selection: "
choice = gets
puts "\nExcellent choice."
choice = case
when 1
puts "\n\nHow many fibonacci numbers would you like? "
limit = gets.to_i
seq.fibo(limit) { |x| puts "Fibonacci number: #{x}\n" }
when 2
puts "\n\nHow many rows of Pascal's Triangle would you like?"
n = gets.to_i
(0..n).each {|num| seq.pascal_triangle_row(num) \
{|row| puts "#{row} "}; puts "\n"}
end
end
How come if I run the code and supply option 2, it still runs the first case?
Your case syntax is wrong. Should be like this:
case choice
when '1'
some code
when '2'
some other code
end
Take a look here.
You also need to compare your variable against strings, as gets reads and returns user input as a string.
Your bug is this: choice = case should be case choice.
You're providing a case statement with no "default" object, so the first clause, when 1, always returns true.
Effectively, you've written: choice = if 1 then ... elsif 2 then ... end
And, as Mladen mentioned, compare strings to strings or convert to int: choice = gets.to_i