value = gets
However, if this is left as it is, a line break will occur when outputting, so use the chomp method.
value = gets.chomp
The to_i method is convenient when you want to calculate the acquired numerical value.
value = gets.to_i
to_i method can convert string to number Conversely, if you want to change a number to a string, use the
a b c
When the values are entered on one line separated by spaces like this, the split method
value = gets.split(" ")
You can get the values in the form of an array by using the split method You can check the contents in the same form as an array like value  and value 
value = gets.chars
a b cWhen the values are entered on one line separated by spaces like this
value = ["a", " ", "b", " ", "c"]Get the values as an array called
value = gets.chomp.split(" ")
By writing like this, the line feed code can also be cut off, which is convenient.
I think this is generally used
value = gets.split(" ").map(&:to_i)
When all the values are numbers, you can get them in the form of an array and convert them to numbers at the same time by writing like this.
value = readlines
redalines can get multi-line strings as a line-by-line array.
Unlike gets, typing a line break does not end keyboard input.
Please let me know if you make a mistake or have an easier way!