In Ruby is there a way to combine all array elements into one string?
Example Array:
@arr = ['<p>Hello World</p>', '<p>This is a test</p>']
Example Output:
<p>Hello World</p><p>This is a test</p>
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6The documentation is your friend! It will help you considerably to study the methods of Array, String, Hash, etc.Mark Thomas– Mark Thomas2010-10-26 00:27:26 +00:00Commented Oct 26, 2010 at 0:27
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4 Answers
Use the Array#join method (the argument to join is what to insert between the strings - in this case a space):
@arr.join(" ")
4 Comments
stevenspiel
what if you were joining digits?
[1,2,3] => 123?
sepp2k
@mr.musicman
join works with enumerables of anything that responds to to_s, including integers, but the result will always be a string. If you want an integer result, you can use to_i on the result.
Frank Koehl
If you initially broke up a multi-line string using
String#lines, you can sanely tied it back together using my_string.join('') (note the empty string argument).
Greg Navis
To add to what @sepp2k said:
join tries #to_str first and #to_s second.While a bit more cryptic than join, you can also multiply the array by a string.
@arr * " "
2 Comments
marcio
besides being cryptic, is there any possible flaw when using this trick?
okket
@marcioAlmada No flaw, just minimal overhead. In array.c the first thing Ruby does is checking for a string type and then calling the join method. Also: pry with show-source rocks! Try for yourself:
$ Array.instance_methods.* ($ is shorthand for show-source)Here's my solution:
@arr = ['<p>Hello World</p>', '<p>This is a test</p>']
@arr.reduce(:+)
=> <p>Hello World</p><p>This is a test</p>
Comments
Another possible implementation for this would be the following:
I'm more used to #inject even though one can use #reduce interchangeably
@arr = ['<p>Hello World</p>', '<p>This is a test</p>']
@arr.inject(:+)
=> <p>Hello World</p><p>This is a test</p>