Ruby hash merge by comparing a value -


i have following array of hashes 

[{:day=>"may 2015", :rent=>0, :bond=>0, :rentinadvance=>0},  {:day=>"may 2015", :rent=>0, :bond=>0, :rentinadvance=>450},  {:day=>"may 2015", :rent=>0, :bond=>750, :rentinadvance=>0},  {:day=>"jun 2015", :rent=>600, :bond=>0, :rentinadvance=>0},  {:day=>"jul 2015", :rent=>600, :bond=>0, :rentinadvance=>0},  {:day=>"dec 2015", :rent=>600, :bond=>0, :rentinadvance=>0}]

i need merge record using day key value, expected result is

[{:day=>"may 2015", :rent=>0, :bond=>750, :rentinadvance=>450},  {:day=>"jun 2015", :rent=>600, :bond=>0, :rentinadvance=>0},  {:day=>"jul 2015", :rent=>600, :bond=>0, :rentinadvance=>0},  {:day=>"dec 2015", :rent=>600, :bond=>0, :rentinadvance=>0}]

thanks in advance..

tldr:

data.group_by |d|   d[:day] end.values.map |days|   days.inject |a,b|     {       day: a[:day],       rent: a[:rent] + b[:rent],       bond: a[:bond] + b[:bond],       rentinadvance: a[:rentinadvance] + b[:rentinadvance]     }   end end

explanation:

let's have data in data variable:

data = [{:day=>"may 2015", :rent=>0, :bond=>0, :rentinadvance=>0},         {:day=>"may 2015", :rent=>0, :bond=>0, :rentinadvance=>450},         {:day=>"may 2015", :rent=>0, :bond=>750, :rentinadvance=>0},         {:day=>"jun 2015", :rent=>600, :bond=>0, :rentinadvance=>0},         {:day=>"jul 2015", :rent=>600, :bond=>0, :rentinadvance=>0},         {:day=>"dec 2015", :rent=>600, :bond=>0, :rentinadvance=>0}]

then can group (group_by) array :day value, 

grouped_data = data.group_by |d|   d[:day] end  # {"may 2015"=> #   [{:day=>"may 2015", :rent=>0, :bond=>0, :rentinadvance=>0}, #    {:day=>"may 2015", :rent=>0, :bond=>0, :rentinadvance=>450}, #    {:day=>"may 2015", :rent=>0, :bond=>750, :rentinadvance=>0}], #  "jun 2015"=>[{:day=>"jun 2015", :rent=>600, :bond=>0, :rentinadvance=>0}], #  "jul 2015"=>[{:day=>"jul 2015", :rent=>600, :bond=>0, :rentinadvance=>0}], #  "dec 2015"=>[{:day=>"dec 2015", :rent=>600, :bond=>0, :rentinadvance=>0}]}

the key of resulting hash date, , value array of data-hashes. interested in values , map array of data-hashes single merged data-hash with:

merged_data = grouped_data.values.map |days|   days.inject |a,b|     {       day: a[:day],       rent: a[:rent] + b[:rent],       bond: a[:bond] + b[:bond],       rentinadvance: a[:rentinadvance] + b[:rentinadvance]     }   end end

the inject merges 2 data-hashes (a , b) new hash. gives final result:

puts merged_data # {:day=>"may 2015", :rent=>0, :bond=>750, :rentinadvance=>450} # {:day=>"jun 2015", :rent=>600, :bond=>0, :rentinadvance=>0} # {:day=>"jul 2015", :rent=>600, :bond=>0, :rentinadvance=>0} # {:day=>"dec 2015", :rent=>600, :bond=>0, :rentinadvance=>0}

ps: might read ruby documentation on methods, if you're not familiar them. i've added link each method used.


Comments

Post a Comment

Popular posts from this blog

c++ - Difference between pre and post decrement in recursive function argument -

i have following sample code used pre-decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(--c); cout << c << endl; return; } } this function give output input 4 : dp3 dp2 dp1 dp0 0 1 2 3 but when use post decrement void function(int c) { if(c == 0) { return; } else { cout << "dp" << c << endl; function(c--); cout << c << endl; return; } } output goes in infinite loop dp4 can explain me in detail why happens ? this happens because function(c--) called same value of c , when finishes c decremented. recursively called, hence called same value no chance of return , hit stack overflow error. assume this, int x = 1, y = 0; y = x++ result y == 1 , x == 2. if y = ++x , bot x , y 2.
Read more

php - Nothing but 'run(); ' when browsing to my local project, how do I fix this? -

i added new project. made mistake in projectname.conf file in sites-available apache2, led me reinstalling apache2. after reinstalling , re-enabling projects on every page of every project .. <body> run(); </body> .. i've run composer update, restarted service, restarted pc, checked config files, tried disabling new project. there nothing in error log, , access.log: 127.0.0.1 - - [15/may/2015:01:40:47 +0200] "get / http/1.1" 304 181 "-" "mozilla/5.0 (x11; ubuntu; linux x86_64; rv:38.0) gecko/20100101 firefox/38.0" maybe i'm forgetting apache2 reinstall? don't think did different last time installed it. looks haven't setup php correctly. take @ this great guide , maybe you're forgetting link php config apache2.
Read more

php - How can I echo out this array? -

i don't know how go grabbing data in variable , put foreach loop. class tree{ private $info = array( array('name'=>'jim','state'=>'nu','company'=>'nu','phone'=>array('cell'=>'5615111111','office'=>'5611111111'),'email'=>array('primary'=>'exs@example.com','ex@there.com')), array('name'=>'joe smith','city'=>'phoenix','phone'=>'4805551111','email'=>'jsmith@some_email.com'), array('name'=>'john doe','city'=>'chandler','company'=>'doe co.','email'=>array('jdoe@gmail.com','personal'=>'email@email.com'),'phone'=>'6025550002') ); } if you're inside of class, can access private variable using $this->variablename . example, i
Read more