Question

我对我的小perl脚本感到困惑。我已经将两个值传递给了例程，但是，只有第一个在子路径中工作。

#!usr/bin/perl 
sub even_number_printer_gen {
    my ( $input1, $input2 ) = @_;

    #my $input1=shift;
    #my $input2=shift;
    print
        "after shifting, the input1 is $input1 and the input2 is $input2\n";
    if ( $input1 % 2 ) { $input1++ }
    if ( $input2 % 2 ) { $input2++ }

    $rs = sub {    #subroutin 1, everytime add 2 in $input1
        print "$input1 ";
        $input1 += 2;
    };
    $rs2 = sub {    #subroutin 2, everytime add 3 in $input2
        print "$input2 ";
        $ipnut2 += 3;
    };
    @rs3 = ( $rs, $rs2 );
    return @rs3;    #return two subroutins as an array
}
@iterator = &even_number_printer_gen( 31, 20 );
for ( $i = 0; $i < 10; $i++ ) {
    &{ $iterator[0] };    #refer subroutin 1
    &{ $iterator[1] };    #refer subroutin 2
    print "\n";
}
print "done!\n";

输出

after shifting, the input1 is 31 and the input2 is 20
32 20 
34 20 
36 20 
38 20 
40 20 
42 20 
44 20 
46 20 
48 20 
50 20 
done!

为什么第二个值不会改变？

Answer 1

您写道：

$ipnut2 += 3;

应该是：

$input2 += 3;

在我的电脑上

f.jardon@xxxxx 11:49:04 ~/tmp
$ cat fixedperl.pl
#!/usr/bin/perl
sub even_number_printer_gen {
    my ( $input1, $input2 ) = @_;

    #my $input1=shift;
    #my $input2=shift;
    print
        "after shifting, the input1 is $input1 and the input2 is $input2\n";
    if ( $input1 % 2 ) { $input1++ }
    if ( $input2 % 2 ) { $input2++ }

    $rs = sub {    #subroutin 1, everytime add 2 in $input1
        print "$input1 ";
        $input1 += 2;
    };
    $rs2 = sub {    #subroutin 2, everytime add 3 in $input2
        print "$input2 ";
        $input2 += 3; ## <<<<====================== HERE IS THE FIX
    };
    @rs3 = ( $rs, $rs2 );
    return @rs3;    #return two subroutins as an array
}
@iterator = &even_number_printer_gen( 31, 20 );
for ( $i = 0; $i < 10; $i++ ) {
    &{ $iterator[0] };    #refer subroutin 1
    &{ $iterator[1] };    #refer subroutin 2
    print "\n";
}
print "done!\n";

f.jardon@xxxxx 11:49:06 ~/tmp
$ ./fixedperl.pl
after shifting, the input1 is 31 and the input2 is 20
32 20
34 23
36 26
38 29
40 32
42 35
44 38
46 41
48 44
50 47
done!

为什么不能转移第二个值？

1 个答案: