I'm trying to take the user's input (numbers separated by commas, e.g., "5,8,11"), and return the equivalent number of "-"s. For example, if the user inputs "4,2,4,5", then the output should be the following:
----
--
----
-----
with each on a new line. I need to take an input string, split it at the commas, which will turn it into an array, and then iterate through the array and print the amount of commas per element.
I tried this,
puts "Enter some numbers"
input = gets.chomp
input.split(',')
input.each do |times|
puts "-" * times
end
which returns a noMethodError. I'm not sure where I am wrong.
Any help would be greatly appreciated.
You need integers for that. Try
input = gets.chomp.split(',').map(&:to_i)
Couple of things...
input.split(',')
This DOES split input, but it doesn't change the contents of the input variable.
What would work...
input = input.split(',')
Secondly, the result will be an array of strings, not integers, so better would be...
input = input.split(',').map(&:to_i)
This will map the string array into an integer array
Related
I have a series of strings that all include 1 or many numbers (a number in this case would be 123,123,123) in the following format
"This is a number 123,124,123"
"These are some more numbers 123,345,123; 231,123,123; 124,152,123"
"This one is an odd situation 123,124,125; 123,123,123; more text"
What is the cleanest way to parse these numbers into either an array or a string that I can split that looks like this?
"123,124,123"
"123,345,123;231,123,123;124,152,123"
"123,124,125;123,123,123;"
Ultimately I want to be able to separate out the numbers like this.
"123,124,123"
"123,345,123" "231,123,123" "124,152,123"
"123,124,125" "123,123,123"
Currently attempting to use
"string".scan( /\d/ )
but obviously this is only giving me the numbers without the commas and also not separated properly.
Do it like this
string.scan(/[\d,]+/)
Another way would be to remove the unwanted characters.
arr = ["This is a number 123,124,123",
"These are some more numbers 123,345,123; 231,123,123; 124,152,123",
"This one is an odd situation 123,124,125; 123,123,123; more text"]
arr.map { |str| str.gsub(/[^\s\d,]+/,'').split }
#=> [["123,124,123"],
# ["123,345,123", "231,123,123", "124,152,123"],
# ["123,124,125", "123,123,123"]]
Regex that matches your numbers is \d{1,3}(,\d{3})*
I have a file with multiple lines. In each line, there two words and a number, split by a comma - for example a, b, 1. It means that string A and string B have the key as 1. I wrote the below piece of code
File.open(ARGV[0], 'r') do |f1|
while line = f1.gets
puts line
end
end
i'm looking for an idea of how to split and copy the characters and number in such a way that the first two words have the last number as key in the hashmap.
Does this work for you?
hash = {}
File.readlines(ARGV[0]).each do |line|
var = line.gsub(' ','').split(',')
hash[var[2]] = var[0],var[1]
end
This would give:
hash['1'] = ['a','b']
I don't know if you want to store number one as an integer or a string, if it's a integer you're looking for, just do var[2].to_i before storing.
Modified your code a little bit, i think it's shorter this way, if i'm in any way wrong, do let me know.
Is it possible to use variables in both fields of the gsub method ?
I'm trying to get this piece of code work :
$I = 0
def random_image
$I.to_s
random = rand(1).to_s
logo = File.read('logo-standart.txt')
logo_aleatoire = logo.gsub(/#{$I}/, random)
File.open('logo-standart.txt', "w") {|file| File.puts logo_aleatoire}
$I.to_i
$I += 1
end
Thanks in advance !
filecontents = File.read('logo-standart.txt')
filecontents.gsub!(/\d+/){rand(100)}
File.open("logo-standart.txt","w"){|f| f << filecontents }
The magic line is the second line.
The gsub! function modifies the string in-place, unlike the gsub function, which would return a new string and leave the first string unmodified.
The single parameter that I passed to gsub! is the pattern to match. Here, the goal is to match any string of one or more digits -- this is the number that you're going to replace. There's no need to loop through all of the possible numbers running gsub on each one. You can even match numbers as high as a googol (or higher) without your program taking longer and longer to run.
The block that gsub! takes is evaluated each time the pattern matches to programmatically generate a replacement number. So each time, you get a different random number. This is different from the more usual form of gsub! that takes two parameters -- there the parameter is evaluated once before any pattern matching occurs, and all matches are replaced by the same string.
Note that the way this is structured, you get a new random number for each match. So if the number 307 appears twice, it turns into two different random numbers.
If you wanted to map 307 to the same random number each time, you could do the following:
filecontents = File.read('logo-standart.txt')
randomnumbers = Hash.new{|h,k| h[k]=rand(100)}
filecontents.gsub!(/\d+/){|match| randomnumbers[match]}
File.open("logo-standart.txt","w"){|f| f << filecontents }
Here, randomnumbers is a hash that lets you look up the numbers and find what random number they correspond to. The block passed when constructing the hash tells the hash what to do when it finds a number that it hasn't seen before -- in this case, generate a new random number, and remember what that random number the mapping. So gsub!'s block just asks the hash to map numbers for it, and randomnumbers takes care of generating a new random number when you encounter a new number from the original file.
I have a string that
contains at least one number
can contain multiple numbers
Some examples are:
https://www.facebook.com/permalink.php?story_fbid=53199604568&id=218700384
https://www.facebook.com/username_13/posts/101505775425651120
https://www.facebook.com/username/posts/101505775425699820
I need a way to extract the longest number from the string. So for the 3 strings above, it would extract
53199604568
101505775425651120
101505775425699820
How can I do this?
#get the lines first
text = <<ENDTEXT
https://www.facebook.com/permalink.php?story_fbid=53199604568&id=218700384
https://www.facebook.com/username_13/posts/101505775425651120
https://www.facebook.com/username/posts/101505775425699820
ENDTEXT
lines = text.split("\n")
#this bit is the actual answer to your question
lines.collect{|line| line.scan(/\d+/).sort_by(&:length).last}
Note that i'm returning the numbers as strings here. You could convert them to numbers with to_i
parse the list (to get an int array), then use the Max function. array.Max for syntax.
s = "https://www.facebook.com/permalink.php?story_fbid=53199604568&id=218700384"
s.scan(/\d+/).max{|a,b| a.length <=> b.length}.to_i
I have strings like this:
https://www.facebook.com/username_with_number_14/posts/101505775425654414
https://www.facebook.com/username/posts/101505775425654466
I need to extract the number on the end of the string in Ruby. In the first string, it is the second and last number, whereas in the second string it is the first, only and last number.
At the moment I am extracting the number like this:
int1 = Regexp.new('.*?(\\d+)',Regexp::IGNORECASE).match()[1]
But when this is applied to the first string, it extracts the number part of the username, not the desired number.
How can I do it so that it will work on both strings?
text = <<ENDTEXT
https://www.facebook.com/username_with_number_14/posts/101505775425654414
https://www.facebook.com/username/posts/101505775425654466
ENDTEXT
p text.lines.map{|line| line.scan(/\d+/).last}
#=> ["101505775425654414", "101505775425654466"]
for me works regexp like this:
^.*?(\d+)$
look here: http://rubular.com/r/CJzsgjedqJ
Try this
int1 = Regexp.new('.*\\/(\\d+)$',Regexp::IGNORECASE).match()[1]
The $ matches the end of the string. So I put all numbers from the last / to the end of the string into the capturing group 1.