Geek asks and answers

Opposite << in ruby

I have a huge string prepared using an operator <<in a loop. In the end, I want to delete the last 2 characters.

some_loop
  str << something
end
str = str[0..-3]

I think the last operation above will consume memory and time, but I'm not sure. I just wanted to see if there is an operation with the opposite effect <<, so I can remove these last 2 characters from one line.

+5
source share
3 answers

In fact, line cutting is already a fast and memory efficient operation, since the contents of the line are not copied until it is really needed.

. double: Ruby ".

, ; java, C.

, :

str = str[0..-3]

, , , . .

+8

, , ? - ?

names = ['Mary', 'John', 'Dave']

res = ''
names.each do |n|
  res << n << ', '
end

res # => 'Mary, John, Dave, '

, .

names.join(', ') # => 'Mary, John, Dave'
+3

: linefeed/newline (CR/LF), String.chomp ( String#chomp!, ).

:

2.times{ string.chop! }


string.chop!
string.chop!
+1

More articles:


All Articles