Is It Ever Necessary to Use 'Chomp' Before Using 'To_I' or 'To_F'

Is it ever necessary to use 'chomp' before using `to_i` or `to_f`?

There is no need to use chomp method because:

String#chomp returns a new String with the given record separator removed from the end of str (if present). If $/ has not been changed from the default Ruby record separator, then chomp also removes carriage return characters (that is it will remove "\n", "\r", and "\r\n"). Here are some examples.

String#to_f returns the result of interpreting leading characters in str as a floating point number. Extraneous characters past the end of a valid number are ignored. If there is not a valid number at the start of str, 0.0 is returned. This method never raises an exception. Here are some examples for to_f.

Whats wrong with the modulus operator in this Ruby code?

Your result will always be false because gets.chomp returns a String:

number = gets.to_i

The above code will work but you must always type an integer. There are better ways to manage checking to see if the input is valid.

So you could check first like this:

number = gets
factors_to_three(number.to_i) if number.is_a?(Integer)

How to return a number using to_i when the input starts with $

Meditate on these:

"$1\n"[1..-1].to_i # => 1
"$1.99\n"[1..-1].to_i # => 1
"$100.99\n"[1..-1].to_i # => 100

This breaks down when there's a leading -:

"-$100.99\n"[1..-1].to_i # => 0

That can be fixed using sub instead of a slice:

"-$100.99\n".sub('$', '').to_i # => -100

The problem is, money is not all integers, so to_i is probably not really what you want. Instead you should be using to_f:

"$1\n".sub('$', '').to_f # => 1.0
"$1.99\n".sub('$', '').to_f # => 1.99
"$100.99\n".sub('$', '').to_f # => 100.99
"-$100.99\n".sub('$', '').to_f # => -100.99
"$-100.99\n".sub('$', '').to_f # => -100.99

Note: It isn't necessary to use chomp to remove the trailing new-line. to_i and to_f will stop when they see a non-digit:

"1\n".to_i # => 1
"1.99\n".to_f # => 1.99

"1 1\n".to_i # => 1
"1.99 2\n".to_f # => 1.99

Again, because of this behavior, "\n" and 1\n or 2\n will be ignored.

Ruby random number generator

number is a number, choice is a string. You need to parse the string for this to work:

choice = gets.chomp.to_i

How to return a number using to_i when the input starts with $

Meditate on these:

"$1\n"[1..-1].to_i # => 1
"$1.99\n"[1..-1].to_i # => 1
"$100.99\n"[1..-1].to_i # => 100

This breaks down when there's a leading -:

"-$100.99\n"[1..-1].to_i # => 0

That can be fixed using sub instead of a slice:

"-$100.99\n".sub('$', '').to_i # => -100

The problem is, money is not all integers, so to_i is probably not really what you want. Instead you should be using to_f:

"$1\n".sub('$', '').to_f # => 1.0
"$1.99\n".sub('$', '').to_f # => 1.99
"$100.99\n".sub('$', '').to_f # => 100.99
"-$100.99\n".sub('$', '').to_f # => -100.99
"$-100.99\n".sub('$', '').to_f # => -100.99

Note: It isn't necessary to use chomp to remove the trailing new-line. to_i and to_f will stop when they see a non-digit:

"1\n".to_i # => 1
"1.99\n".to_f # => 1.99

"1 1\n".to_i # => 1
"1.99 2\n".to_f # => 1.99

Again, because of this behavior, "\n" and 1\n or 2\n will be ignored.

Check if a number entered by the user with gets.chomp is a float in ruby

puts "What are the first number you want to divide"
number1 = gets.chomp.to_i
=> 100
puts "What is the second number?"
number2 = gets.chomp.to_i
=> 3

# Regular math
result_a = number1 / number2
puts "#{number1} / #{number2} = #{result_a}"
=> 100 / 3 = 33 # Integer class persists...

# Use a ruby library instead! Numeric#divmod
result_b = number1.divmod(number2)
puts "Result: #{result_b}"
=> [33, 1] # [quotient, modulus]

How can I divide two strings in Ruby with gets.chomp?

The command gets stands for "get a string". You are trying to divide a string by a number.

Change the line

lbs = gets.chomp

to

lbs = gets.chomp.to_i

to convert the string to an integer, or use to_f if you prefer using floats.

How can I divide two strings in Ruby with gets.chomp?

The command gets stands for "get a string". You are trying to divide a string by a number.

Change the line

lbs = gets.chomp

to

lbs = gets.chomp.to_i

to convert the string to an integer, or use to_f if you prefer using floats.

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