Sum the value of array in hash
RubyHashRuby Problem Overview
This is my array
[{:amount=>10, :gl_acct_id=>1, :alt_amount=>20}, {:amount=>20, :gl_acct_id=>2
, :alt_amount=>30}]
i want result
[{:amount => 30}] or {:amount = 30}
Any idea?
Ruby Solutions
Solution 1 - Ruby
Ruby versions >= 2.4.0 has an Enumerable#sum method. So you can do
arr.sum {|h| h[:amount] }
Solution 2 - Ruby
array.map { |h| h[:amount] }.sum
Solution 3 - Ruby
You can use inject to sum all the amounts. You can then just put the result back into a hash if you need to.
arr = [{:amount=>10, :gl_acct_id=>1, :alt_amount=>20}, {:amount=>20, :gl_acct_id=>2, :alt_amount=>30}]
amount = arr.inject(0) {|sum, hash| sum + hash[:amount]} #=> 30
{:amount => amount} #=> {:amount => 30}
Solution 4 - Ruby
This is one way to do it:
a = {amount:10,gl_acct_id:1,alt_amount:20},{amount:20,gl_acct_id:2,alt_amount:30}
a.map {|h| h[:amount] }.reduce(:+)
However, I get the feeling that your object model is somewhat lacking. With a better object model, you would probably be able to do something like:
a.map(&:amount).reduce(:+)
Or even just
a.sum
Note that as @sepp2k pointed out, if you want to get out a Hash, you need to wrap it in a Hash again.
Solution 5 - Ruby
[{
:amount=>10,
:gl_acct_id=>1,
:alt_amount=>20
},{
:amount=>20,
:gl_acct_id=>2,
:alt_amount=>30
}].sum { |t| t[:amount] }
Solution 6 - Ruby
why not pluck?
ary = [{:amount=>10, :gl_acct_id=>1, :alt_amount=>20}, {:amount=>20, :gl_acct_id=>2, :alt_amount=>30}]
ary.pluck(:amount).sum
# for more reliability
ary.pluck(:amount).compact.sum
Solution 7 - Ruby
If we are having only a single element in all the hashes in a array and also keys were different ?
Here is the solution I found:
Sum of the values:
x = [{"a" => 10},{"b" => 20},{"d" => 30}]
Solution:
x.inject(0){|sum, hash| sum+= hash.values.join.to_i }
Also we can do:
x.inject(0){|sum, hash| sum+= hash.values.sum }
Solution 8 - Ruby
total=0
arr = [{:amount=>10, :gl_acct_id=>1, :alt_amount=>20}, {:amount=>20, :gl_acct_id=>2, :alt_amount=>30}]
arr.each {|x| total=total+x[:amount]}
puts total