有没有一种不那么笨拙的替代方法来复制“n"?数组元素? [英] Is there a less clumsy alternative for copying up to "n" array elements?

问题描述

在许多@choices
的世界里有了 $limit 可以做什么，
生活提出了许多@options
但有时只有一两个.
为了尽量减少线路噪音
Tim Toady 可以做什么?

In a world of many @choices
With a $limit to what one can do,
Life proposes many @options
But at times just one or two.
In a bid to minimize line noise
What can Tim Toady do?

以下是我想到的几种方法，但它们看起来很笨拙.当然还有更优雅的 DWIM 方式:

Here are a few ways I've thought of, but they just seem so clumsy. Surely there's a more elegant way to DWIM:

• 详细单行

my @choices = @options <= $limit ? @options : @options[0..$limit-1];  # Blech

切片控件

my @choices = @options[0..(@options <= $limit ? $#options : $limit - 1)]; # Even worse

切片里面的俗气切片

my @choices = @options[0..($#options, $limit-1 )[@options > $limit]];  # Crazy eyes

更清晰的意图，但超过两行

my @choices = @options;
   @choices = @options[0..$limit-1] if $limit < @options;

推荐答案

@choices = @options; splice @choices, $limit;  # "splice() offset past end" before v5.16

也可以在一条语句中完成！

It can also be done in a single statement!

@choices = splice @{[@options]}, 0, $limit;

还有

splice @{$choices_ref=[@options]}, $limit;  # Warns "splice() offset past end" before v5.16
splice $choices_ref=[@options], $limit;     # Ditto. Requires Perl v5.14. "Experimental"

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