perl 判斷數組相等的三種方法

1.數組相等，數組成員相同，位置也相同

一般的如果判斷@array1 等於 @array2

a.數組長度相同 $#array1=$#array2, 比較數組長度，不能使用length函數，length只適用string類型

數組參數傳遞，不能直接傳遞

 

sub compare()
{
        my $flag=0;
        my ($first,$second)=@_;
        if (@$first==@$second) # the number of the array , don't use length() 
        {
                for(my $i=0;$i<@$first;$i++)
                {
                        if($first->[$i]!=$second->[$i])
                        {
                                $flag=1;
                                print "$first->[$i]==$second->[$i]\n";
                        }
                }
        }
        else
        {
                $flag=1;
        }
        if( $flag==1)
        {
                print "two arrays are not equal\n";
        }
        else
        {
                 print "two arrays are  equal\n";
        }
}

my @a=(1,2,3,4,5);
my @b=(1,2,3,4,5);
&compare(\@a,\@b);

輸出：two arrays are  equal

my @a=(1,2,3,4,5);
my @b=(1,2,3,4,5,6);
&compare(\@a,\@b);

輸出：two arrays are not equal

2.以上代碼可以簡化

使用智能匹配 ~~

注意 ：智能匹配是從5.10.0開始的

所以要require 5.10.0

@a ~~ @b 兩個數組相同

$x ~~ @a   x在數組a中

$x ~~%hash  相當於 exists $hash{$x};

 

#/usr/bin/perl -w 
use strict;
require 5.10.0;
sub compare()
{
        my $flag=0;
        my ($first,$second)=@_;
        if( @$first ~~ @$second )
        {
        print "two arrays are  equal\n";

            }
         else
       {
        print "two arrays are not equal\n";
        }      
}                     

 3.使用 模塊

#!/usr/bin/perl
use strict;

use Array::Compare;
my @array1=1..10;
my @array2=1..11;
my @array3=1..10;
print "compare array1 and array2\n";
&check(\@array1,\@array2);
print "compare array1 and array3\n";
&check(\@array1,\@array3);

sub check
{
    my ($ref1,$ref2)=@_;
    my $comp=Array::Compare->new;
    if($comp->compare($ref1,$ref2))
    {
        print "the two arrays are the same\n";
    }
    else
    {
        print "the two arrays not the same\n";
    }
}

運行結果：

D:\>perl suzu.pl
compare array1 and array2
the two arrays not the same
compare array1 and array3
the two arrays are the same