Perl |反转一个数组
在 Perl 中反转数组或字符串。
迭代方式: 从 0 到数组中间迭代数组。 用 arr[size-i]元素替换 arr[i]元素。
#Perl code to reverse an array iteratively
#declaring an array of integers
@arr = (2, 3, 4, 5, 6, 7);
# Store length on array in $n variable
$n = $#arr;
#Print the original array
print "The original array is : ";
for $i (0 .. $#arr)
{
print $arr[$i], " ";
}
#run a loop from 0 to mid of array
for my $i (0 .. $#arr/2)
{
#swap the current element with size-current element
$tmp = $arr[$i];
$arr[$i] = $arr[$n-$i];
$arr[$n-$i] = $tmp;
}
#Print the reversed array
print "\nThe reversed array is : ";
for $i (0 .. $#arr)
{
print $arr[$i], " ";
}
Output:
The original array is : 2 3 4 5 6 7
The reversed array is : 7 6 5 4 3 2
使用内置函数: Perl 有一个内置函数来反转数组、字符串或数字。
#Perl code to reverse an array using inbuilt function reverse
#declaring an array of integers
@arr = (2, 3, 4, 5, 6, 7);
#Print the original array
print "The original array is : ";
for $i (0 .. $#arr)
{
print $arr[$i], " ";
}
#store the reversed array in @rev_arr
@rev_arr = reverse(@arr);
#Print the reversed array
print "\nThe reversed array is : ";
for $i (0 .. $#rev_arr)
{
print $rev_arr[$i], " ";
}
Output:
The original array is : 2 3 4 5 6 7
The reversed array is : 7 6 5 4 3 2
