Convert an Array of Integers into an Array of Strings in Ruby

Convert array of strings to an array of integers

To convert a string to number you have the to_i method.

To convert an array of strings you need to go through the array items and apply to_i on them. You can achieve that with map or map! methods:

> ["", "22", "14", "18"].map(&:to_i)
# Result: [0, 22, 14, 18]

Since don't want the 0 - just as @Sebastian Palma said in the comment, you will need to use an extra operation to remove the empty strings: (The following is his answer! Vote for his comment instead :D)

> ["", "22", "14", "18"].reject(&:empty?).map(&:to_i)
# Result: [22, 14, 18]

the difference between map and map! is that map will return a new array, while map! will change the original array.

How to convert a string of ids inside an array to array of ids without string in ruby?

You're trying to split an array, try to split a string instead:

["4,5,6"].first.split(',')
#=> ["4", "5", "6"]

After that you can simply convert it to an array of ints:

["4", "5", "6"].map(&:to_i)
#=> [4, 5, 6]

How to convert an array of string integers to an array of integers? Ruby

all_ages = ["11", "9", "10", "8", "9"]

Code

p all_ages.map(&:to_i).sum

Or

p all_ages.map { |x| x.to_i }.sum

Output

47

How to convert an array of integers to an integer

[nil, 3, 4, 2].join.to_i
#=> 342

Return an array with integers in stead of strings

newArray <<"#{total}" # WRONG

You're pushing strings into the array with the expectation of getting integers in the end. Change the above line to:

newArray << total

And just FYI, you can use map to clean things up here.

def your_method(array)
  array.map.with_index do |element, index|
    element + index
  end
end

Convert string to int array in Ruby

A simple one liner would be:

s.each_char.map(&:to_i)
#=> [2, 3, 5, 3, 4]

If you want it to be error explicit if the string is not contained of just integers, you could do:

s.each_char.map { |c| Integer(c) }

This would raise an ArgumentError: invalid value for Integer(): if your string contained something else than integers. Otherwise for .to_i you would see zeros for characters.

Ruby array to string conversion

I'll join the fun with:

['12','34','35','231'].join(', ')
# => 12, 34, 35, 231

EDIT:

"'#{['12','34','35','231'].join("', '")}'"
# => '12','34','35','231'

Some string interpolation to add the first and last single quote :P

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