２つの値を交換する

明解Ｃ言語 入門編 > 10. ポインタ >

２つの値を交換する

Perl

sub swap1
{
    my ($nx, $ny) = @_;
    my $tmp = $nx;
    $nx = $ny;
    $ny = $tmp;
}

sub swap2
{
    my ($nx, $ny) = @_;
    my $tmp = $$nx;
    $$nx = $$ny;
    $$ny = $tmp;
}

$na = 57;
$nb = 21;

printf("整数Ａ：%d\n", $na);
printf("整数Ｂ：%d\n", $nb);
print "\n";

&swap1($na, $nb);

printf("整数Ａ：%d\n", $na);
printf("整数Ｂ：%d\n", $nb);
print "\n";

$na = 57;
$nb = 21;
&swap2(\$na, \$nb);

printf("整数Ａ：%d\n", $na);
printf("整数Ｂ：%d\n", $nb);
print "\n";

$na = 57;
$nb = 21;
($na, $nb) = ($nb, $na);

printf("整数Ａ：%d\n", $na);
printf("整数Ｂ：%d\n", $nb);
print "\n";

実行結果

L:\>perl lesson_10_077.pl

整数Ａ：57

整数Ｂ：21
整数Ａ：57

整数Ｂ：21
整数Ａ：21

整数Ｂ：57
整数Ａ：21

整数Ｂ：57