javascript - Sort the json in the array -

i want sort array, according property such this:

[ {num:5},{num:3},{num:6},{num:9} ]  

after sort, want get

[ {num:3},{num:5},{num:6},{num:9} ]  

how in javascript?

a sort function (literal) returns 1, -1, 0 ascending, descending , equal respectively.

array.sort(function(a, b) {       return a.num - b.num });