# A = \[false\]; a\[0\] &&= true

**URL:** <https://www.ruby-forum.com/t/a-false-a-0-true/137495>\
**Category:** Development\
**Created:** [May 13, 2008, 5:47pm UTC](https://www.ruby-forum.com/t/a-false-a-0-true/137495 "2008-05-13T17:47:03Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Tanaka\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/c67d28/32.png) [@Tanaka\_A](https://www.ruby-forum.com/u/Tanaka_A)\
**Post date:** [May 13, 2008, 5:47pm UTC](https://www.ruby-forum.com/t/a-false-a-0-true/137495/1 "2008-05-13T17:47:03Z")

</div>

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]