无法解决的perl错误？

Question

use strict;
my @array = ();
my @nums = [3, 4];
foreach my $i ( 0 .. 10 ) {
    foreach my $j ( 0 .. 10 ) {
        $nums[0] = 4+1;
        push @{ $array[$i] }, @nums;
    }
}
print $array[6][2][0]. "\n";

正如人们可以看到他们是否运行代码,这不能正常运行.但是,如果你注释掉"$ nums [0] = 4 + 1;"这一行,它运行正常.到底是怎么回事？只能将不可变数组推送到其他数组吗？

Answer 1

@nums是一个数组,并分配给数组引用(带括号[]).因此,将其更改为正确的数组声明:my @nums = (3, 4);

use strict;
use Data::Dump;

my @array = ();
my @nums = (3, 4);
foreach my $i ( 0 .. 10 ) {
    foreach my $j ( 0 .. 10 ) {
        $nums[0] = 4+1;
        push @{ $array[$i] }, @nums;
    }
}

dd @array;

#-- output:
(
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
  [5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4],
)