配列とポインタ

C Delphi

明解Ｃ言語 入門編 > 10. ポインタ >

配列とポインタ

C



#include <stdio.h>
int main(int argc, char* argv[])

{

    int i;

    int vc[] = {10, 20, 30, 40, 50};

    int* ptr = &vc[0];
    for (i = 0; i < 5; i++)

    {

        printf("vc[%d] = %d    "   , i, vc[i]);

        printf("ptr[%d] = %d    "  , i, ptr[i]);

        printf("*(ptr + %d) = %d\n", i, *(ptr + i));

    }

    puts("");
    ptr = vc;

    for (i = 0; i < 5; i++)

    {

        printf("vc[%d] = %d    "   , i, vc[i]);

        printf("ptr[%d] = %d    "  , i, ptr[i]);

        printf("*(ptr + %d) = %d\n", i, *(ptr + i));

    }
    return 0;

}

実行結果



R:\>lesson078\Project1.exe

vc[0] = 10    ptr[0] = 10    *(ptr + 0) = 10

vc[1] = 20    ptr[1] = 20    *(ptr + 1) = 20

vc[2] = 30    ptr[2] = 30    *(ptr + 2) = 30

vc[3] = 40    ptr[3] = 40    *(ptr + 3) = 40

vc[4] = 50    ptr[4] = 50    *(ptr + 4) = 50
vc[0] = 10    ptr[0] = 10    *(ptr + 0) = 10

vc[1] = 20    ptr[1] = 20    *(ptr + 1) = 20

vc[2] = 30    ptr[2] = 30    *(ptr + 2) = 30

vc[3] = 40    ptr[3] = 40    *(ptr + 3) = 40

vc[4] = 50    ptr[4] = 50    *(ptr + 4) = 50

Delphi



program Project1;
{$APPTYPE CONSOLE}
uses

    SysUtils;
procedure main();

var

    i:    Integer;

    vc:   array[1..5] of Integer;

    ptr: ^Integer;

begin

    vc[1] := 10;

    vc[2] := 20;

    vc[3] := 30;

    vc[4] := 40;

    vc[5] := 50;
    ptr := @vc[1];
    for i := Low(vc) to High(vc) do

    begin

        write(Format('vc[%d] = %d    '   , [i, vc[i]]));

        Writeln(Format('*(ptr + %d) = %d', [i, ptr^]));
        Inc(ptr);

    end;
//  ptr := vc; これは、エラー

end;
begin

    main;

end.

実行結果



S:\>lesson078\Project1.exe

vc[1] = 10    *(ptr + 1) = 10

vc[2] = 20    *(ptr + 2) = 20

vc[3] = 30    *(ptr + 3) = 30

vc[4] = 40    *(ptr + 4) = 40

vc[5] = 50    *(ptr + 5) = 50