given the following string examples:
human_id_2, human_id_44, human_id_3123121, human_id_11111
I'm trying to loop through and extract just the ID/integer.
params.each do |key, value|
if (key.to_s[/human_id_.*/])
theId= key.to_s[/human_id_.*/]
....
end
end
I'm expecting theId to loop through an be 2, 44, etc...
Any idea why theId is not being set properly?
Why not just replace "human_id_" with ""? No need to do regexp for that:
theId = key.gsub("human_id_", "")
This will work and filter out if there's a mixture:
string = "human_id_2, blahblah blah_other_stuff234234, human_id_44, what_up_4545, human_id_3123121, human_id_11111, sdjfhksfh$##$4343894"
string.scan(/(?<=human_id_).*?(?!\d)/)
=> ["2", "44", "3123121", "11111"]
Notice how it ignores the unneeded data.
"human_id_2, human_id_44, human_id_3123121, human_id_11111".scan(/\d+/)
# => ["2", "44", "3123121", "11111"]
Related
Question:
Create a method for Array that returns a hash having 'key' as length of the element and value as an array of all the elements of that length. Make use of Array#each.
Returned Hash should be sorted by key.
I have tried to do it through Hash sorting over length. I have almost resolved it using another method but I want to use split and hash to achieve expected output.
Can anyone suggest any amendments in my code below?
Input argument:
array-hash.rb "['abc','def',1234,234,'abcd','x','mnop',5,'zZzZ']"
Expected output:
{1=>["x", "5"], 3=>["abc", "def", "234"], 4=>["1234", "abcd", "mnop", "zZzZ"]}
class String
def key_length(v2)
hash = {}
v2.each do |item|
item_length = item.to_s.length
hash[item_length] ||= []
hash[item_length].push(item)
end
Hash[hash.sort]
end
end
reader = ''
if ARGV.empty?
puts 'Please provide an input'
else
v1 = ARGV[0]
v2 = v1.tr("'[]''",'').split
p reader.key_length(v2)
end
Actual output:
{35=>["abc,def,1234,234,abcd,x,mnop,5,zZzZ"]}
Given the array (converted from string, note integers as string between ""):
ary = str[1..-2].delete('\'').split(',')
ary #=> ["abc", "def", "1234", "234", "abcd", "x", "mnop", "5", "zZzZ"]
The most "idiomatic" way should be using group_by:
ary.group_by(&:size)
If you want to use each, then you could use Enumerable#each_with_object, where the object is an Hash#new with an empty array as default:
ary.each_with_object(Hash.new{ |h,k| h[k] = []}) { |e, h| h[e.size] << e }
Which is the same as
res = Hash.new{ |h,k| h[k] = []}
ary.each { |e| res[e.size] << e }
Not sure why you need to monkeypatch* array here, is this a school exercise or something?
I think your bug is you need to pass in the comma delimiter arg to split.
I would solve the underlying problem as a reduce/inject/fold thing, myself.
s = "['abc','def',1234,234,'abcd','x','mnop',5,'zZzZ']"
splits = s.tr("'[]''",'').split(',') # need to pass in the comma for the split
Hash[splits.inject({}) { |memo,s| memo[s.length] ||= []; memo[s.length] << s; memo }.sort] # doesn't use Array.each but?
{1=>["x", "5"], 3=>["def", "234"], 4=>["1234", "abcd", "mnop"],
5=>["['abc"], 6=>["zZzZ']"]}
I have a string which returns duration in the below format.
"152M0S" or "1H22M32S"
I need to extract hours, minutes and seconds from it as numbers.
I tried like the below with regex
video_duration.scan(/(\d+)?.(\d+)M(\d+)S/)
But it does not return as expected. Anyone has any idea where I am going wrong here.
"1H22M0S".scan(/\d+/)
#=> ["1", "22", "0']
You can use this expression: /((?<h>\d+)H)?(?<m>\d+)M(?<s>\d+)S/.
"1H22M32S".match(/((?<h>\d+)H)?(?<m>\d+)M(?<s>\d+)S/)
#=> #<MatchData "1H22M32S" h:"1" m:"22" s:"32">
"152M0S".match(/((?<h>\d+)H)?(?<m>\d+)M(?<s>\d+)S/)
#=> #<MatchData "152M0S" h:nil m:"152" s:"0">
Question mark after group makes it optional. To access data: $~[:h].
If you want to extract numbers, you could do as :
"1H22M32S".match(/(?<hour>(\d+))H(?<min>(\d+))M(?<sec>(\d+))S/i).captures
# => ["1", "22", "32"]
"1H22M32S".match(/(?<hour>(\d+))H(?<min>(\d+))M(?<sec>(\d+))S/i)['min']
# => "22"
"1H22M32S".match(/(?<hour>(\d+))H(?<min>(\d+))M(?<sec>(\d+))S/i)['hour']
# => "1"
Me, I'd hashify:
def hashify(str)
str.gsub(/\d+[HMS]/).with_object({}) { |s,h| h[s[-1]] = s.to_i }
end
hashify "152M0S" #=> {"M"=>152, "S"=>0}
hashify "1H22M32S" #=> {"H"=>1, "M"=>22, "S"=>32}
hashify "32S22M11H" #=> {"S"=>32, "M"=>22, "H"=>11}
hashify "1S" #=> {"S"=>1}
I'm trying to solve this with a regex pattern, and even though my test passes with this solution, I would like split to only have ["1", "2"] inside the array. Is there a better way of doing this?
irb testing:
s = "//;\n1;2" # when given a delimiter of ';'
s2 = "1,2,3" # should read between commas
s3 = "//+\n2+2" # should read between delimiter of '+'
s.split(/[,\n]|[^0-9]/)
=> ["", "", "", "", "1", "2"]
Production:
module StringCalculator
def self.add(input)
solution = input.scan(/\d+/).map(&:to_i).reduce(0, :+)
input.end_with?("\n") ? nil : solution
end
end
Test:
context 'when given a newline delimiter' do
it 'should read between numbers' do
expect(StringCalculator.add("1\n2,3")).to eq(6)
end
it 'should not end in a newline' do
expect(StringCalculator.add("1,\n")).to be_nil
end
end
context 'when given different delimiter' do
it 'should support that delimiter' do
expect(StringCalculator.add("//;\n1;2")).to eq(3)
end
end
Very simple using String#scan :
s = "//;\n1;2"
s.scan(/\d/) # => ["1", "2"]
/\d/ - A digit character ([0-9])
Note :
If you have a string like below then, you should use /\d+/.
s = "//;\n11;2"
s.scan(/\d+/) # => ["11", "2"]
You're getting data that looks like this string: //1\n212
If you're getting the data as a file, then treat it as two separate lines. If it's a string, then, again, treat it as two separate lines. In either case it'd look like
//1
212
when output.
If it's a string:
input = "//1\n212".split("\n")
delimiter = input.first[2] # => "1"
values = input.last.split(delimiter) # => ["2", "2"]
If it's a file:
line = File.foreach('foo.txt')
delimiter = line.next[2] # => "1"
values = line.next.chomp.split(delimiter) # => ["2", "2"]
Suppose we have the string "aaabbbccc" and want to use the String#insert to convert the string to "aaa<strong>bbb</strong>ccc". Is this the best way to insert multiple values into a Ruby string using String#insert or can multiple values simultaneously be added:
string = "aaabbbccc"
opening_tag = '<strong>'
opening_index = 3
closing_tag = '</strong>'
closing_index = 6
string.insert(opening_index, opening_tag)
closing_index = 6 + opening_tag.length # I don't really like this
string.insert(closing_index, closing_tag)
Is there a way to simultaneously insert multiple substrings into a Ruby string so the closing tag does not need to be offset by the length of the first substring that is added? I would like something like this one liner:
string.insert(3 => '<strong>', 6 => '</strong>') # => "aaa<strong>bbb</strong>ccc"
Let's have some fun. How about
class String
def splice h
self.each_char.with_index.inject('') do |accum,(c,i)|
accum + h.fetch(i,'') + c
end
end
end
"aaabbbccc".splice(3=>"<strong>", 6=>"</strong>")
=> "aaa<strong>bbb</strong>ccc"
(you can encapsulate this however you want, I just like messing with built-ins because Ruby lets me)
How about inserting from right to left?
string = "aaabbbccc"
string.insert(6, '</strong>')
string.insert(3, '<strong>')
string # => "aaa<strong>bbb</strong>ccc"
opening_tag = '<strong>'
opening_index = 3
closing_tag = '</strong>'
closing_index = 6
string = "aaabbbccc"
string[opening_index...closing_index] =
opening_tag + string[opening_index...closing_index] + closing_tag
#=> "<strong>bbb</strong>"
string
#=> "aaa<strong>bbb</strong>ccc"
If your string is comprised of three groups of consecutive characters, and you'd like to insert the opening tag between the first two groups and the closing tag between the last two groups, regardless of the size of each group, you could do that like this:
def stuff_tags(str, tag)
str.scan(/((.)\2*)/)
.map(&:first)
.insert( 1, "<#{tag}>")
.insert(-2, "<\/#{tag}>")
.join
end
stuff_tags('aaabbbccc', 'strong') #=> "aaa<strong>bbb</strong>ccc"
stuff_tags('aabbbbcccccc', 'weak') #=> "aa<weak>bbbb</weak>cccccc"
I will explain the regex used by scan, but first would like to show how the calculations proceed for the string 'aaabbbccc':
a = 'aaabbbccc'.scan(/((.)\2*)/)
#=> [["aaa", "a"], ["bbb", "b"], ["ccc", "c"]]
b = a.map(&:first)
#=> ["aaa", "bbb", "ccc"]
c = b.insert( 1, "<strong>")
#=> ["aaa", "<strong>", "bbb", "ccc"]
d = c.insert(-2, "<\/strong>")
#=> ["aaa", "<strong>", "bbb", "</strong>", "ccc"]
d.join
#=> "aaa<strong>bbb</strong>ccc"
We need two capture groups in the regex. The first (having the first left parenthesis) captures the string we want. The second captures the first character, (.). This is needed so that we can require that it be followed by zero or more copies of that character, \2*.
Here's another way this can be done:
def stuff_tags(str, tag)
str.chars.chunk {|c| c}
.map {|_,a| a.join}
.insert( 1, "<#{tag}>")
.insert(-2, "<\/#{tag}>")
.join
end
The calculations of a and b above change to the following:
a = 'aaabbbccc'.chars.chunk {|c| c}
#=> #<Enumerator: #<Enumerator::Generator:0x000001021622d8>:each>
# a.to_a => [["a",["a","a","a"]],["b",["b","b","b"]],["c",["c","c","c"]]]
b = a.map {|_,a| a.join }
#=> ["aaa", "bbb", "ccc"]
I have an array, which is comprising of different kind of objects. But I would like to get only the string instances. What i wrote as below :
ary = ["11",1,2,"hi",[11]]
ary.select{|e| e.instance_of? String } # => ["11", "hi"]
I am looking for an elegant way of doing this, if any.
I would do as below using Enumerable#grep :
Returns an array of every element in enum for which Pattern === element. If the optional block is supplied, each matching element is passed to it, and the block’s result is stored in the output array.
ary = ["11",1,2,"hi",[11]]
ary.grep(String) # => ["11", "hi"]
You may want to try Object#is_a? method:
ary = ["11", 1, 2, "hi", [11]]
ary.select{|e| e.is_a? String }
# Output
=> ["11", "hi"]
Can't do better than grep, but here's another:
ary.group_by(&:class)[String] # => ["11", "hi"]