I have an array of hashes like so:
[{\"testPARAM1\"=>\"testVAL1\"}, {\"testPARAM2\"=>\"testVAL2\"}]
And I\'m trying to map this onto sin
Here you can use either inject or reduce from Enumerable class as both of them are aliases of each other so there is no performance benefit to either.
sample = [{"testPARAM1"=>"testVAL1"}, {"testPARAM2"=>"testVAL2"}]
result1 = sample.reduce(:merge)
# {"testPARAM1"=>"testVAL1", "testPARAM2"=>"testVAL2"}
result2 = sample.inject(:merge)
# {"testPARAM1"=>"testVAL1", "testPARAM2"=>"testVAL2"}
How about:
h = [{"testPARAM1"=>"testVAL1"}, {"testPARAM2"=>"testVAL2"}]
r = h.inject(:merge)
You could compose Enumerable#reduce
and Hash#merge
to accomplish what you want.
input = [{"testPARAM1"=>"testVAL1"}, {"testPARAM2"=>"testVAL2"}]
input.reduce({}, :merge)
is {"testPARAM2"=>"testVAL2", "testPARAM1"=>"testVAL1"}
Reducing an array sort of like sticking a method call between each element of it.
For example [1, 2, 3].reduce(0, :+)
is like saying 0 + 1 + 2 + 3
and gives 6
.
In our case we do something similar, but with the merge function, which merges two hashes.
[{:a => 1}, {:b => 2}, {:c => 3}].reduce({}, :merge)
is {}.merge({:a => 1}.merge({:b => 2}.merge({:c => 3})))
is {:a => 1, :b => 2, :c => 3}
Use #inject
hashes = [{"testPARAM1"=>"testVAL1"}, {"testPARAM2"=>"testVAL2"}]
merged = hashes.inject({}) { |aggregate, hash| aggregate.merge hash }
merged # => {"testPARAM1"=>"testVAL1", "testPARAM2"=>"testVAL2"}