Delphi2005 Studi Catatan 3— - Penelitian pada parameter array

有如下代码:

Perubahan Prosedur (A: Array Int32);

Prosedur Change0 (var A: Array dari int32);

Jenis

ta = array [0..10] dari int32;

Prosedur Change2 (A: TA);

Prosedur Perubahan3 (var A: TA);

Var

AA: TA;

BB: Array Int32;

Implementasi

{$ autobox on}

Perubahan Prosedur (A: Array Int32);

Mulai

A [0]: = 123;

A: = BB;

Akhir;

Prosedur Change0 (var A: Array dari int32);

Mulai

A [0]: = 123;

A: = BB;

Akhir;

Prosedur Change2 (A: TA);

Mulai

A [0]: = 123;

A: = BB;

Akhir;

Prosedur Perubahan3 (var A: TA);

Mulai

A [0]: = 123;

A: = BB;

Akhir;

然后执行下面的语句

SetLength (bb, 11); bb [0]: = 5678;

aa: = ta (& array.createInstance (typeof (int32), 11));

AA [0]: = 0;

Ubah (AA);

MessageBox.Show (aa [0] .tosting ());

If & object (aa) = & object (bb) lalu MassageBox.show ('=');

aa: = ta (& array.createInstance (typeof (int32), 11));

AA [0]: = 0;

Change0 (AA);

MessageBox.Show (aa [0] .tosting ());

If & object (aa) = & object (bb) lalu MassageBox.show ('=');

aa: = ta (& array.createInstance (typeof (int32), 11));

AA [0]: = 0;

Change2 (AA);

MessageBox.Show (aa [0] .tosting ());

If & object (aa) = & object (bb) lalu MassageBox.show ('=');

aa: = ta (& array.createInstance (typeof (int32), 11));

AA [0]: = 0;

Perubahan3 (aa);

MessageBox.Show (aa [0] .tosting ());

If & object (aa) = & object (bb) lalu MassageBox.show ('=');

结果发现 Array Int32 方式, 可以改变数组元素的值, 但不能改变数组 akan

Var array dari int32 既可以改变数组的值, 又可以改变变傘的榖地址, 输出 5678 menit

ta 方式, 不能改变数组元素級級級, 但是却很奇怪倪倪倪,

Var ta 方式 可仏 可以改变数组元素 hindari, 但是却不是 123?

反汇编结果如下

Metode Publik Static Void Change (Int32 [] A) CIL dikelola

{

// Ukuran kode: 13 byte (s)

.Maxstack

L_0000: LDARG.

L_0001: LDC.I4.0

L_0002: LDC.I4.S

L_0004: Stelem.I4

L_0005: ldsfld int32 [] winform.units.winform :: bb

L_000A: Starg.sa

L_000C: ret

}

 .Metod public static void change0 (int32 [] & a) cil dikelola {// ukuran kode: 14 byte (s) i4.s 123 l_0005: stelem.i4 l_0006: ldarg.0 l_0007: ldsfld int32 [] winform.units. WinForm :: BB L_000C: Sting.Ref L_000D: ret}

 .Metod public static void change2 (int32 [] a) cil dikelola { // ukuran kode: 42 byte (s) :: clone () l_0006: castclass int32 [] l_000b: starg.sa l_000d: ldarg.0 l_000e: ldc. I4.0 L_000F: ldc.i4.s 123 l_0011: stelem.i4 l_0012: ldsfld int32 [] winform.unit. l_0 :: stloc.0 l_0023: ltloc.0 l_0024: hubungi void [mscorlib] system.array :: copy ([mscorlib] system.array, [mscorlib] system.array, int32) l_0029: ret}

 .Method public static void change3 (int32 [] & a) cil dikelola { // ukuran kode: 31 byte .0 l_0003: ldc.i4.s 123 l_0005: stelem.i4 ld_0006: ldsfld int32 [] winform :: BB L_000B: LDLEN L_000D: STELC.0 L_000E: LDARG. 0 L_0019: Hubungi void [mscorlib] system.array :: copy ([mscorlib] system.ararray, [mscorlib] system.array, int32) l_001e: ret}
结论 !!
使 TheArray of int32 方式, 实际上应于 C#的可变数目参数, 即 paraams int32 []
这种参数方式是传递的数组馰地地址 (即参数的值), 而不是存放数组馰地址的变 Ubah
加上 var 修饰饰, 即加 odp 修饰饰, 传饰, 是存放数组馰组馰组馰组地组地址?
使 Bahasa Inggris, 则在值进进进进进进进进进进进进进进进进进进进进进进进 Who, 变数组首地址, 也不改变原组值
加 odp, 好像传递的是变量身眰址, 迿里还是没看懂是为什什什什么。
对应的 C#代码为
Public static void change (params int [] a) {a [0] = 0x7b; A = winform.bb;} 
 Public static void change0 (params ref int [] a) {a [0] = 0x7b; A = winform.bb;} 
 Public static void change2 (int [] a) {a = (int []) a.clone (); A [0] = 0x7b; Int num1 = winform.bb.length; If (num1> 11) {num1 = 11; } Array.copy (winform.bb, a, nun1);}; 
 Public static void change3 (ref int [] a) {a [0] = 0x7b; Int num1 = winform.bb.length; If (num1> 11) {num1 = 11; } Array.copy (winform.bb, a, nun1);};