问题
Say I've got an array like this:
array_1 = [0, 0, 1, 2, 3, 0]
and another one like this:
array_2 = [4, 5, 6]
How can I create an array like this, such that each 0 in the array_1 is replaced by the first and subsequent elements of the array_2?:
[4, 5, 1, 2, 3, 6]
That is, every time we encounter a 0 in the first array, we'd like to replace it with the result of array_2.shift.
回答1:
This one is shorter but the shift method it will modify array_2 in-place.
array_1.map {|x| x == 0 ? array_2.shift : x}
The following uses an enumerator object with external iteration and will not modify any of the original arrays.
e = array_2.each
array_1.map {|x| x == 0 ? e.next : x}
回答2:
You could do something like this, iterate and shift when you encounter a 0
array_1.each_with_index do |val, i|
array_1[i] = array_2.shift if val == 0
end
来源：https://stackoverflow.com/questions/38274802/replace-all-zeros-in-array-with-elements-of-another-array