[PerlChina] Re: Question about if (@array)

Ray 写道:
> Hi, all
>
> Would you explain the output of the following perl codes?
>
> question 1:
> Is the sentence "if (@array) " same as "if ( scalar(@array) )"??
> question 2:
> what's the difference of "undef $variable " and "delete $variable"??
>
> Thanks,
> Ray
>
>
>
> -------------------------------------------
> code----------------------------------
> #!/usr/bin/perl
>
> use strict;
> use warnings;
>
> my @host = ();
> my @host1 = ('fdfd', 'fdfdfd');
> my @host2 = undef;
>
> if ( @host ) {
> print "host ok\n";
> } else {
> print "host fail\n";
> }
>
> if ( @host1 ) {
> print "host1 ok\n";
> } else {
> print "host1 fail\n";
> }
>
> if ( @host2 ) {
> print "host2 ok\n";
> } else {
> print "host2 fail\n";
> }
> -------------------------------------------
> code----------------------------------
>
> and the output is :
> host fail
> host1 ok
> host2 ok
>
>
> >
>
>

1）反正是标量环境，你自己转换，或者perl帮你转换，应该没区别的。
2）delete可以操作标量吗？

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