Question

There are some arrays in Ruby (is this case there 4 array)

array1 = [{key="label1.1", value="label1.2"}, {key="label1.2", value="label1.2"}]
array2 = [{key="label2.1", value="label2.2"}]

array3 = []
array4 = nil
result_array = array1 | array2 | array3 | array4 

Each of arrays has the same structure as others: it’s hash values. How many elements in it, if it’s nil or empty – it’s not known.

So I need result_array to look:

[{key="label1.1", value="label1.2"}, {key="label1.2", value="label1.2"}, {key="label2.1", value="label2.2"}]

However that code is going to cause an exception because array4 is equal to nil.

Is there any, Ruby, way to check if an array is not nil and not empty and if so, then merge it to result_array?

Answer 1

[array1, array2, array3, array4].compact.reduce([], :|)