我想了解如何在 Solidity 中對以下數組進行編碼。

動態數組

例如，以下內容：

function getDynamicUintArray() public pure returns (uint[] memory) {
       uint[] memory array = new uint[](3);
       array[0] = 1;
       array[1] = 2;
       array[2] = 3;
       return array;
   }

遵循文件中的正式規範：我們將按照以下步驟進行：

enc(array) = enc(len(array)) enc(array[0]) enc(array[1]) enc([array[2])

這將導致以下結果：

0000000000000000000000000000000000000000000000000000000000000003
0000000000000000000000000000000000000000000000000000000000000001
0000000000000000000000000000000000000000000000000000000000000002
0000000000000000000000000000000000000000000000000000000000000003

問題是當我為部署在Rinkeby上的合約執行此操作時，並執行以下 RPC 呼叫：

curl <rinkeby_endpoint> -X POST --data '{"jsonrpc":"2.0", "method":"eth_call", "params":[{"from": "<send_address>", "to": "0xaD2bbEeF0A1FCa287d7a1d6cFa925E8C79cC7aC0", "data": "0x421fc531"}, "latest"], "id":4}'

我得到以下結果：

{"jsonrpc":"2.0","id":4,"result":"0x00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000003000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000003"}

0000000000000000000000000000000000000000000000000000000000000020開頭有一個額外的。究竟是什麼額外的？

結構數組

此外，在編碼結構時。下面的例子：

struct Foo {
       string id;
       string name;
   }

當我執行以下功能時：

function getMultipleFoo() public pure returns (Foo[] memory) {
       Foo[3] multipleFoo;
       Foo memory _foo = Foo("id", "name");
       multipleFoo[0] = _foo;
       multipleFoo[1] = _foo;
       multipleFoo[2] = _foo;
       return multipleFoo;
   }

我應該收到類似的東西：

0000000000000000000000000000000000000000000000000000000000000060 == offset of first struct
0000000000000000000000000000000000000000000000000000000000000120 == offset of second struct
00000000000000000000000000000000000000000000000000000000000001e0 == offset of third struct

0000000000000000000000000000000000000000000000000000000000000040 == offset of first struct string
0000000000000000000000000000000000000000000000000000000000000080 == offset of second struct string
0000000000000000000000000000000000000000000000000000000000000002 == first string length
6964000000000000000000000000000000000000000000000000000000000000 == "id" hex representation
0000000000000000000000000000000000000000000000000000000000000004 == second string length
6e616d6500000000000000000000000000000000000000000000000000000000 == "name" hex representation

0000000000000000000000000000000000000000000000000000000000000040 == offset of first struct string
0000000000000000000000000000000000000000000000000000000000000080 == offset of second struct string
0000000000000000000000000000000000000000000000000000000000000002 == first string length
6964000000000000000000000000000000000000000000000000000000000000 == "id" hex representation
0000000000000000000000000000000000000000000000000000000000000004 == second string length
6e616d6500000000000000000000000000000000000000000000000000000000 == "name" hex representation

0000000000000000000000000000000000000000000000000000000000000040 == offset of first struct string
0000000000000000000000000000000000000000000000000000000000000080 == offset of second struct string
0000000000000000000000000000000000000000000000000000000000000002 == first string length
6964000000000000000000000000000000000000000000000000000000000000 == "id" hex representation
0000000000000000000000000000000000000000000000000000000000000004 == second string length
6e616d6500000000000000000000000000000000000000000000000000000000 == "name" hex representation

但是，當我獲得該函式呼叫的返回值時，我會0000000000000000000000000000000000000000000000000000000000000020像第一種情況一樣在開始時獲得一個額外的值。

如果您作為參數傳遞或從函式接收非規範類型的值，例如字元串或數組，則其描述的偏移量將在相應參數或返回值的位置傳遞。

因此，對於兩個 bytese32 數組，它將是 (array1

$$ 2 $$, 數組2$$ 3 $$):

000 0000000000000000000000000000000000000000000000000000000000000040
020 00000000000000000000000000000000000000000000000000000000000000a0

040 0000000000000000000000000000000000000000000000000000000000000002
060 0000000000000000000000000000000000000000000000000000000000000101
080 0000000000000000000000000000000000000000000000000000000000000102

0a0 0000000000000000000000000000000000000000000000000000000000000003
0c0 0000000000000000000000000000000000000000000000000000000000000201
0e0 0000000000000000000000000000000000000000000000000000000000000202
100 0000000000000000000000000000000000000000000000000000000000000203

不幸的是，我無法再找到描述此內容的文​​檔，因此附上我使用 ROC API 的說明的連結（這是我在 habr.com 上的文章的翻譯） https://github.com/oldmadjackal/人群/blob/master/Doc/Wiki/Habr-Ethereum-RPC_API.docx

引用自：https://ethereum.stackexchange.com/questions/91571