Versions Compared


  • This line was added.
  • This line was removed.
  • Formatting was changed.


Code Block
class MyException extends Exception{}
def exception(){ throw new MyException() }
def i, a, b

i= 4
a= new Object[i][i=3] //first subscript evaluated before next one
assert a.size() == 4 && a[0].size() == 3

a= [ 11, 12, 13, 14 ] as Object[]
b= [ 3, 2, 1, 0 ] as Object[]
assert a[(a=b)[2]] == 12
    //outside of subscript evaluated before inside, ie, a[b[2]] or a[1] or 12

i= 1 //if what's outside subscript throws exception, subscript isn't evaluated
try{ exception()[i=2] }catch(e){ assert i == 1 }

i= 1
a= new Object[2][2]
  //if subscript evaluation throws exception, subscripts to right not evaluated
try{ a[ exception() ][i=2] }catch(e){ assert i == 1 }

//index evaluated before indexing occurs (including checking whether 
//what's outside subscript is null)...
a= null
try{ a[exception()]; assert 0 }catch(e){ assert e instanceof MyException }
    //NullPointerException never occurs here
i= 1
try{ a[i=2]; assert 0 }
catch(e){ assert i == 2 && e instanceof NullPointerException }

Implementing an ArrayList with an Object Array

ArrayLists are implemented with object arrays internally. Each ArrayList instance has a capacity, the size of a fixed-size array used to store the elements. This array is always at least as large as the list size, and its capacity grows automatically as elements are added to the list. To see the internal capacity of lists constructed with various values: