２つの値を交換する

明解Ｃ言語入門編 > 10. ポインタ >

C



#include <stdio.h>
void swap1(int nx, int ny)

{

    int tmp = nx;

    nx = ny;

    ny = tmp;

}
void swap2(int* nx, int* ny)

{

    int tmp = *nx;

    *nx = *ny;

    *ny = tmp;

}
int main(int argc, char* argv[])

{

    int na = 57;

    int nb = 21;
    printf("整数Ａ：%d\n", na);

    printf("整数Ｂ：%d\n", nb);

    puts("");
    swap1(na, nb);
    printf("整数Ａ：%d\n", na);

    printf("整数Ｂ：%d\n", nb);

    puts("");
    na = 57;

    nb = 21;

    swap2(&na, &nb);
    printf("整数Ａ：%d\n", na);

    printf("整数Ｂ：%d\n", nb);

    puts("");
    return 0;

}

実行結果

R:\>lesson077\Project1.exe
整数Ａ：57
整数Ｂ：21

整数Ａ：57
整数Ｂ：21

整数Ａ：21
整数Ｂ：57

C++



#include <stdio.h>
void swap1(int nx, int ny)

{

    int tmp = nx;

    nx = ny;

    ny = tmp;

}
void swap3(int& nx, int& ny)

{

    int tmp = nx;

    nx = ny;

    ny = tmp;

}
int main(int argc, char* argv[])

{

    int na = 57;

    int nb = 21;
    printf("整数Ａ：%d\n", na);

    printf("整数Ｂ：%d\n", nb);

    puts("");
    swap1(na, nb);
    printf("整数Ａ：%d\n", na);

    printf("整数Ｂ：%d\n", nb);

    puts("");
    na = 57;

    nb = 21;

    swap3(na, nb);
    printf("整数Ａ：%d\n", na);

    printf("整数Ｂ：%d\n", nb);

    puts("");
    return 0;

}

実行結果

T:\>lesson077\Project1.exe
整数Ａ：57
整数Ｂ：21

整数Ａ：57
整数Ｂ：21

整数Ａ：21
整数Ｂ：57

Delphi



program Project1;
{$APPTYPE CONSOLE}
uses

    SysUtils;
procedure swap1(nx:Integer; ny:Integer);

var

    tmp: Integer;

begin

    tmp := nx;

    nx  := ny;

    ny  := tmp;

end;
procedure swap2(var nx:Integer; var ny:Integer);

var

    tmp: Integer;

begin

    tmp := nx;

    nx  := ny;

    ny  := tmp;

end;
procedure swap3(nx:PInteger; ny:PInteger);

var

    tmp: Integer;

begin

    tmp := nx^;

    nx^ := ny^;

    ny^ := tmp;

end;
procedure main();

var

    na, nb: Integer;

begin

    na := 57;

    nb := 21;
    Writeln(Format('整数Ａ：%d', [na]));

    Writeln(Format('整数Ｂ：%d', [nb]));

    Writeln('');
    swap1(na, nb);
    Writeln(Format('整数Ａ：%d', [na]));

    Writeln(Format('整数Ｂ：%d', [nb]));

    Writeln('');
    na := 57;

    nb := 21;

    swap2(na, nb);
    Writeln(Format('整数Ａ：%d', [na]));

    Writeln(Format('整数Ｂ：%d', [nb]));

    Writeln('');
    na := 57;

    nb := 21;

    swap3(@na, @nb);
    Writeln(Format('整数Ａ：%d', [na]));

    Writeln(Format('整数Ｂ：%d', [nb]));

    Writeln('');

end;
begin

    main;

end.

実行結果

S:\>lesson077\Project1.exe
整数Ａ：57
整数Ｂ：21

整数Ａ：57
整数Ｂ：21

整数Ａ：21
整数Ｂ：57

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

Ruby

def swap1(nx, ny)
    tmp = nx
    nx  = ny
    ny  = tmp
end

def swap2(nx, ny)
    return ny, nx
end

na = 57
nb = 21

printf("整数Ａ：%d\n", na)
printf("整数Ｂ：%d\n", nb)
puts ""

swap1(na, nb)

printf("整数Ａ：%d\n", na)
printf("整数Ｂ：%d\n", nb)
puts ""

na, nb = nb, na

printf("整数Ａ：%d\n", na)
printf("整数Ｂ：%d\n", nb)
puts ""

na = 57
nb = 21
na, nb = swap2(na, nb)

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

実行結果

L:\>ruby l:\lesson_10_077.rb
整数Ａ：57
整数Ｂ：21

整数Ａ：57
整数Ｂ：21

整数Ａ：21
整数Ｂ：57