javascript - lodash _.sortedIndex returns last index element -

i'm using lodash _.sortedindex determine position element should go.

if array being checked small enough works perfectly. array can grow quite large , after has increased size _.sortedindex returns last element of array instead of actual position

var checkobject = {name: john, lastname: doe} var arrayofobjects = [1...25]; //the objects similar layout checkobject var position = _.sortedindex(arrayofobjects, checkobject, 'name') 

this works fine, , position returned appropriate spot.

however in instance below:

var checkobject = {name: john, lastname: doe} var arrayofobjects = [1...75]; //the objects similar layout checkobject var position = _.sortedindex(arrayofobjects, checkobject, 'name') 

it seems either return correct position or return 76

is there way ensure returned position correct?

this call called function inside angular using following:

$scope.$evalasync(     function (data) {         somefunctiontocheckindex(data)     } );