Are these two Ruby methods with a hash parameter equivalent? If not, why not? -


first version of method:

def method(param1, param2={})   meth_x(param2).meth_y(param1)   meth_z   #... end

second version of method (notice second param2)...

def method(param1, param2={})   meth_x(param2={}).meth_y(param1)   meth_z   #... end

i assume these 2 methods equivalent , i'd go first 1 (less typing, less redundancy).

however, i'm curious if these expected behave differently and, if so, why.

in second, set param2 empty hash before giving parameter meth_x. in method definition param2 = {} means if parameter omitted, set default empty hash, in meth_x(param2 = {}) means drop original content of param2 , replace empty hash, giving meth_x.

irb(main):001:0> = {:alma => 2} => {:alma=>2} irb(main):002:0> puts {:alma=>2} => nil irb(main):003:0> puts(a) {:alma=>2} => nil irb(main):004:0> puts(a = {}) {} => nil

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