perl - 在perl脚本中拼接

Question

my @writers = qw( Horace Ovid Virgil Asimov Heinlein Dante );
my @contemporary = splice @writers, 3, 2;
print join(' ', @contemporary);

输出

Asimov Heinlein

---

my @writers = qw( Horace Ovid Virgil Asimov Heinlein Dante );
splice @writers, 3, 2;
print join(' ', @writers); # Horace Ovid Virgil Dante

输出

Horace Ovid Virgil Dante

这些脚本有什么区别。为什么它显示不同的输出？

Answer 1

这里

 my @contemporary = splice @writers, 3, 2;
 print join(' ', @contemporary);

返回被移除的元素

在这里

splice @writers,3,2;
print join(' ', @writers)

它只是打印数组的元素

例如在标量上下文中

 my $contemporary = splice @writers, 3, 2;
 print $contemporary;

它将打印最后一个被删除的元素

来自 perldoc

Removes the elements designated by OFFSET and LENGTH from an array, and replaces them with the elements of LIST, if any. In list context, returns the elements removed from the array. In scalar context, returns the last element removed, or undef if no elements are removed. The array grows or shrinks as necessary. If OFFSET is negative then it starts that far from the end of the array. If LENGTH is omitted, removes everything from OFFSET onward. If LENGTH is negative, removes the elements from OFFSET onward except for -LENGTH elements at the end of the array. If both OFFSET and LENGTH are omitted, removes everything. If OFFSET is past the end of the array, Perl issues a warning, and splices at the end of the array.