Appending new data to existing field of Json data type

Hello,

As i am new to postgresql, i am learning through experimenting things.

i have a table with json data type field, so there is some data for
example :

{ [ { a:b, b:c } ] }

and now if i append data then it should be like :

{ [ { a:b, b:c }, { e:f, g:h } ] }

Is there any way to achieve this. please help.!
I have Postgresql 9.3.5.
--
Regards :
Venktesh Guttedar.