Use interpolation instead of concatenation:
reportStr = "In the first quarter we sold #{myArray[3]} #{myArray[0]}(s)."
It's more idiomatic, more efficient, requires less typing and automatically calls to_s
for you.
Вопрос
My question is about how to convert array elements to string in ruby 1.9 without getting the brackets and quotation marks. I've got an array (DB extract), from which I want to use to create a periodic report.
myArray = ["Apple", "Pear", "Banana", "2", "15", "12"]
In ruby 1.8 I had the following line
reportStr = "In the first quarter we sold " + myArray[3].to_s + " " + myArray[0].to_s + "(s)."
puts reportStr
Which produced the (wanted) output
In the first quarter we sold 2 Apple(s).
The same two lines in ruby 1.9 produce (not wanted)
In the first quarter we sold ["2"] ["Apple"] (s).
After reading in the documentation Ruby 1.9.3 doc#Array#slice I thought I could produce code like
reportStr = "In the first quarter we sold " + myArray[3] + " " + myArray[0] + "(s)."
puts reportStr
which returns a runtime error
/home/test/example.rb:450:in `+': can't convert Array into String (TypeError)
My current solution is to remove brackets and quotation marks with a temporary string, like
tempStr0 = myArray[0].to_s
myLength = tempStr0.length
tempStr0 = tempStr0[2..myLength-3]
tempStr3 = myArray[3].to_s
myLength = tempStr3.length
tempStr3 = tempStr3[2..myLength-3]
reportStr = "In the first quarter we sold " + tempStr3 + " " + tempStr0 + "(s)."
puts reportStr
which in general works.
However, what would be a more elegant "ruby" way how to do that?
Решение 2
Use interpolation instead of concatenation:
reportStr = "In the first quarter we sold #{myArray[3]} #{myArray[0]}(s)."
It's more idiomatic, more efficient, requires less typing and automatically calls to_s
for you.
Другие советы
You can use the .join
method.
For example:
my_array = ["Apple", "Pear", "Banana"]
my_array.join(', ') # returns string separating array elements with arg to `join`
=> Apple, Pear, Banana
And if you need to do this for more than one fruit the best way is to transform the array and the use the each statement.
myArray = ["Apple", "Pear", "Banana", "2", "1", "12"]
num_of_products = 3
tranformed = myArray.each_slice(num_of_products).to_a.transpose
p tranformed #=> [["Apple", "2"], ["Pear", "1"], ["Banana", "12"]]
tranformed.each do |fruit, amount|
puts "In the first quarter we sold #{amount} #{fruit}#{amount=='1' ? '':'s'}."
end
#=>
#In the first quarter we sold 2 Apples.
#In the first quarter we sold 1 Pear.
#In the first quarter we sold 12 Bananas.
You can think of this as arrayToString()
array = array * " "
E.g.,
myArray = ["One.","_1_?! Really?!","Yes!"]
=>
"One.","_1_?! Really?!","Yes!"
myArray = myArray * " "
=>
"One. _1_?! Really?! Yes."