Get Substring After the First = Symbol in Ruby

Get substring after the first = symbol in Ruby

Not exactly .after, but quite close to:

string.partition('=').last

http://www.ruby-doc.org/core-1.9.3/String.html#method-i-partition

Get substring after the first = symbol in Ruby

Not exactly .after, but quite close to:

string.partition('=').last

http://www.ruby-doc.org/core-1.9.3/String.html#method-i-partition

How to extract part of the string which comes after given substring?

Suppose your url is saved in a variable called url.
Then the following should return 1234

url.match(/subfolder\/(\d*)/)[1]

Explanation:

url.match(/     # call the match function which takes a regex
  subfolder\/   # search for the first appearance of the string 'subfolder/'
                # note: we must escape the `/` so we don't end the regex early
  (\d*)         # match any number of digits in a capture group,
/)[1]           # close the regex and return the first capture group

Return string until matched string in Ruby

String splitting is definitely easier and more readable than trying to extract the portion of the string using a regex. For the latter case, you would need a capture group to get the first match. It will be the same as string splitting

string.split(/#|Apt/, 2).first

How to get a substring from the beginning till the end of a word that starts with a with a given substring - Ruby

Use Regexp:

a = 'Metrics testSomeMetrics gets initial metrics data'
b = 'test'
a.match(/^.*#{b}\w*/).to_s

Where:

• ^ — start of the string.
• .* — zero or more of any single character.
• #{b} — your string.
• \w* — zero or more of any word character.

UPDATE

Add \b to get /^.*\b#{b}\w*/ so that it b will be exactly a start of a new string.

Select all characters in a string until a specific character Ruby

You can avoid creating an unnecessary Array (like Array#split) or using a Regex (like Array#gsub) by using.

a = "2.452811139617034,42.10874821716908|3.132087902867818,42.028314077306646|-0.07934861041448178,41.647538468746916|-0.07948265046522918,41.64754863599606"

a[0,a.index('|')]
#=>"2.452811139617034,42.1087482171"

This means select characters at positions 0 up to the index of the first pipe (|). Technically speaking it is start at position 0 and select the length of n where n is the index of the pipe character which works in this case because ruby uses 0 based indexing.

As @CarySwoveland astutely pointed out the string may not contain a pipe in which case my solution would need to change to

#to return entire string
a[0,a.index('|') || a.size]
# or
b = a.index(?|) ? a[0,b] : a
# or to return empty string
a[0,a.index('|').to_i]
# or to return nil
a[0,a.index(?|) || -1]

Ruby: How to get the first character of a string

You can use Ruby's open classes to make your code much more readable. For instance, this:

class String
  def initial
    self[0,1]
  end
end

will allow you to use the initial method on any string. So if you have the following variables:

last_name = "Smith"
first_name = "John"

Then you can get the initials very cleanly and readably:

puts first_name.initial   # prints J
puts last_name.initial    # prints S

The other method mentioned here doesn't work on Ruby 1.8 (not that you should be using 1.8 anymore anyway!--but when this answer was posted it was still quite common):

puts 'Smith'[0]           # prints 83

Of course, if you're not doing it on a regular basis, then defining the method might be overkill, and you could just do it directly:

puts last_name[0,1] 

Ruby - slice all characters till underscore in a string

"solution_10"[/(?<=_).*/]
#⇒ "10"

or simply just get digits until the end of the line:

"solution_10"[/\d+\z/]
#⇒ "10"

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