a = [false] e$B$N$H$-e(B a[0] &&= true e$B$H$$$&<0$NCM$,e(B nil
e$B$K$J$j$^e(B
e$B$9!#e(B
% ./ruby -ve ’
a = [false]
p(a[0] &&= true)
p a
’
ruby 1.9.0 (2008-05-13 revision 16404) [i686-linux]
nil
[false]
1.8 e$B$G$Oe(B false e$B$K$J$j$^$9!#e(B
% ruby-1.8 -ve ’
a = [false]
p(a[0] &&= true)
p a
’
ruby 1.8.7 (2008-05-07 patchlevel 5000) [i686-linux]
false
[false]