Update Tutorials

changes.txt

@@ -23,3 +23,19 @@ docs/ethers-101/01_HelloVitalik/HelloVitalik.js docs/ethers-101/02_Provider/Prov
 Changes in docs/solidity-104:
 docs/ethers-101/01_HelloVitalik/HelloVitalik.js docs/ethers-101/02_Provider/Provider.js docs/ethers-101/03_ReadContract/ReadContract.js docs/ethers-101/04_SendETH/SendETH.js docs/ethers-101/05_WriteContract/WriteContract.js docs/ethers-101/06_DeployContract/DeployContract.js docs/ethers-101/07_Event/Event.js docs/ethers-101/08_ContractListener/ContractListener.js docs/ethers-101/09_EventFilter/EventFilter.js docs/ethers-101/10_Units/Units.js docs/ethers-102/11_StaticCall/readme.md docs/ethers-102/11_StaticCall/staticCall.js docs/ethers-102/12_ERC721Check/ERC721Check.js docs/ethers-102/12_ERC721Check/readme.md docs/ethers-102/13_EncodeCalldata/EncodeCalldata.js docs/ethers-102/14_HDwallet/HDwallet.js docs/ethers-102/14_HDwallet/readme.md docs/ethers-102/15_MultiTransfer/MultiTransfer.js docs/ethers-102/15_MultiTransfer/readme.md docs/ethers-102/16_MultiCollect/MultiCollect.js docs/ethers-102/16_MultiCollect/readme.md docs/ethers-102/17_MerkleTree/MerkleTree.js docs/ethers-102/18_Signature/Signature.js docs/ethers-102/18_Signature/readme.md docs/ethers-102/19_Mempool/Mempool.js docs/ethers-102/19_Mempool/readme.md docs/ethers-102/20_DecodeTx/DecodeTx.js docs/ethers-102/20_DecodeTx/img/20-3.png docs/ethers-102/20_DecodeTx/img/20-4.png docs/ethers-102/20_DecodeTx/readme.md docs/ethers-102/21_VanityAddress/readme.md docs/ethers-102/23_Frontrun/Frontrun.sol docs/ethers-102/23_Frontrun/frontrun.js docs/ethers-102/23_Frontrun/img/23-2.png docs/ethers-102/23_Frontrun/img/23-3.png docs/ethers-102/23_Frontrun/readme.md docs/ethers-102/24_ERC20Check/readme.md docs/ethers-102/25_Flashbots/Flashbots.js docs/ethers-102/25_Flashbots/img/25-4.png docs/ethers-102/25_Flashbots/img/25-5.png docs/ethers-102/25_Flashbots/readme.md docs/solidity-101/01_HelloWeb3/HelloWeb3.sol docs/solidity-101/01_HelloWeb3/img/1-2.png docs/solidity-101/01_HelloWeb3/readme.md docs/solidity-101/02_ValueTypes/ValueTypes.sol docs/solidity-101/02_ValueTypes/readme.md docs/solidity-101/03_Function/Function.sol docs/solidity-101/03_Function/readme.md docs/solidity-101/04_Return/Return.sol docs/solidity-101/04_Return/readme.md docs/solidity-101/05_DataStorage/DataStorage.sol docs/solidity-101/05_DataStorage/readme.md docs/solidity-101/06_ArrayAndStruct/ArrayAndStruct.sol docs/solidity-101/06_ArrayAndStruct/readme.md docs/solidity-101/07_Mapping/Mapping.sol docs/solidity-101/07_Mapping/readme.md docs/solidity-101/08_InitialValue/InitialValue.sol docs/solidity-101/08_InitialValue/readme.md docs/solidity-101/09_Constant/Constant.sol docs/solidity-101/09_Constant/readme.md docs/solidity-101/10_InsertionSort/InsertionSort.sol docs/solidity-101/10_InsertionSort/readme.md docs/solidity-101/11_Modifier/Owner.sol docs/solidity-101/11_Modifier/img/11-1.jpg docs/solidity-101/11_Modifier/img/11-2.jpg docs/solidity-101/11_Modifier/img/11-3.jpg docs/solidity-101/11_Modifier/readme.md docs/solidity-101/12_Event/Event.sol docs/solidity-101/12_Event/readme.md docs/solidity-101/13_Inheritance/Inheritance.sol docs/solidity-101/13_Inheritance/ModifierInheritance.sol docs/solidity-101/13_Inheritance/readme.md docs/solidity-101/14_Interface/Interface.sol docs/solidity-101/14_Interface/img/14-2.png docs/solidity-101/14_Interface/readme.md docs/solidity-101/15_Errors/Error.sol docs/solidity-101/15_Errors/readme.md docs/solidity-102/16_Overloading/Overloading.sol docs/solidity-102/16_Overloading/readme.md docs/solidity-102/17_Library/Library.sol docs/solidity-102/17_Library/readme.md docs/solidity-102/18_Import/Yeye.sol docs/solidity-102/18_Import/readme.md docs/solidity-102/19_Fallback/Fallback.sol docs/solidity-102/19_Fallback/readme.md docs/solidity-102/20_SendETH/SendETH.sol docs/solidity-102/20_SendETH/readme.md docs/solidity-102/21_CallContract/CallContract.sol docs/solidity-102/21_CallContract/readme.md docs/solidity-102/22_Call/Call.sol docs/solidity-102/22_Call/readme.md docs/solidity-102/23_Delegatecall/Delegatecall.sol docs/solidity-102/23_Delegatecall/readme.md docs/solidity-102/24_Create/Create.sol docs/solidity-102/24_Create/readme.md docs/solidity-102/25_Create2/create2test.js docs/solidity-102/25_Create2/readme.md docs/solidity-102/26_DeleteContract/DeleteContract.sol docs/solidity-102/26_DeleteContract/img/26-1.png docs/solidity-102/26_DeleteContract/img/26-2.png docs/solidity-102/26_DeleteContract/readme.md docs/solidity-102/27_ABIEncode/ABIEncode.sol docs/solidity-102/27_ABIEncode/readme.md docs/solidity-102/28_Hash/Hash.sol docs/solidity-102/28_Hash/readme.md docs/solidity-102/29_Selector/Selector.sol docs/solidity-102/29_Selector/img/29-2.png docs/solidity-102/29_Selector/img/29-3.png docs/solidity-102/29_Selector/readme.md docs/solidity-102/30_TryCatch/TryCatch.sol docs/solidity-102/30_TryCatch/readme.md docs/solidity-103/31_ERC20/ERC20.sol docs/solidity-103/31_ERC20/IERC20.sol docs/solidity-103/31_ERC20/readme.md docs/solidity-103/32_Faucet/Faucet.sol docs/solidity-103/32_Faucet/IERC20.sol docs/solidity-103/32_Faucet/readme.md docs/solidity-103/33_Airdrop/Airdrop.sol docs/solidity-103/33_Airdrop/IERC20.sol docs/solidity-103/33_Airdrop/readme.md docs/solidity-103/34_ERC721/ERC721.sol docs/solidity-103/34_ERC721/String.sol docs/solidity-103/34_ERC721/WTFApe.sol docs/solidity-103/34_ERC721/readme.md docs/solidity-103/35_DutchAuction/DutchAuction.sol docs/solidity-103/35_DutchAuction/readme.md docs/solidity-103/36_MerkleTree/MerkleTree.sol docs/solidity-103/36_MerkleTree/readme.md docs/solidity-103/37_Signature/Signature.sol docs/solidity-103/37_Signature/readme.md docs/solidity-103/38_NFTSwap/NFTSwap.sol docs/solidity-103/38_NFTSwap/readme.md docs/solidity-103/39_Random/Random.sol docs/solidity-103/39_Random/RandomNumberConsumer.sol docs/solidity-103/39_Random/img/39-2.png docs/solidity-103/39_Random/img/39-3.png docs/solidity-103/39_Random/img/39-4.png docs/solidity-103/39_Random/img/39-5.png docs/solidity-103/39_Random/img/39-6.png docs/solidity-103/39_Random/img/39-7.png docs/solidity-103/39_Random/readme.md docs/solidity-103/40_ERC1155/BAYC1155.sol docs/solidity-103/40_ERC1155/readme.md docs/solidity-103/41_WETH/readme.md docs/solidity-103/42_PaymentSplit/PaymentSplit.sol docs/solidity-103/42_PaymentSplit/readme.md docs/solidity-103/43_TokenVesting/readme.md docs/solidity-103/44_TokenLocker/readme.md docs/solidity-103/45_Timelock/Timelock.sol docs/solidity-103/45_Timelock/readme.md docs/solidity-103/46_ProxyContract/ProxyContract.sol docs/solidity-103/46_ProxyContract/readme.md docs/solidity-103/47_Upgrade/Upgrade.sol docs/solidity-103/47_Upgrade/readme.md docs/solidity-103/48_TransparentProxy/TransparentProxy.sol docs/solidity-103/48_TransparentProxy/readme.md docs/solidity-103/49_UUPS/UUPS.sol docs/solidity-103/49_UUPS/readme.md docs/solidity-103/50_MultisigWallet/MultisigWallet.sol docs/solidity-103/50_MultisigWallet/readme.md docs/solidity-104/S01_ReentrancyAttack/ReentrancyAttack.sol docs/solidity-104/S01_ReentrancyAttack/readme.md docs/solidity-104/S02_SelectorClash/SelectorClash.sol docs/solidity-104/S02_SelectorClash/readme.md docs/solidity-104/S03_Centralization/Centralization.sol docs/solidity-104/S03_Centralization/readme.md docs/solidity-104/S04_AccessControlExploit/AccessControlExploit.sol docs/solidity-104/S04_AccessControlExploit/readme.md docs/solidity-104/S05_Overflow/Overflow.sol docs/solidity-104/S05_Overflow/readme.md docs/solidity-104/S06_SignatureReplay/SingatureReplay.sol docs/solidity-104/S06_SignatureReplay/readme.md docs/solidity-104/S07_BadRandomness/BadRandomness.sol docs/solidity-104/S07_BadRandomness/readme.md docs/solidity-104/S08_ContractCheck/ContractCheck.sol docs/solidity-104/S08_ContractCheck/readme.md docs/solidity-104/S09_DoS/DoS.sol docs/solidity-104/S09_DoS/readme.md docs/solidity-104/S10_Honeypot/Honeypot.sol docs/solidity-104/S10_Honeypot/readme.md docs/solidity-104/S11_Frontrun/Frontrun.sol docs/solidity-104/S11_Frontrun/frontrun.js docs/solidity-104/S11_Frontrun/readme.md docs/solidity-104/S12_TxOrigin/readme.md docs/solidity-104/S13_UncheckedCall/UncheckedCall.sol docs/solidity-104/S13_UncheckedCall/readme.md docs/solidity-104/S14_TimeManipulation/readme.md docs/solidity-104/S14_TimeManipulation/src/TimeManipulation.sol docs/solidity-104/S14_TimeManipulation/test/TimeManipulation.t.sol docs/solidity-104/S15_OracleManipulation/readme.md docs/solidity-104/S15_OracleManipulation/src/Oracle.sol docs/solidity-104/S15_OracleManipulation/test/Oracle.t.sol docs/solidity-104/S16_NFTReentrancy/NFTReentrancy.sol docs/solidity-104/S16_NFTReentrancy/readme.md docs/ethers-102/21_VanityAddress/BulkVanityAddress.js docs/solidity-101/05_DataStorage/img/5-5.png docs/solidity-101/05_DataStorage/img/5-6.png docs/solidity-101/06_ArrayAndStruct/img/6-4.png docs/solidity-101/06_ArrayAndStruct/img/6-5.png docs/solidity-101/11_Modifier/img/11-4.jpg docs/solidity-101/12_Event/img/12-4.png docs/solidity-101/13_Inheritance/DiamondInheritance.sol docs/solidity-101/14_Interface/AbstractDemo.sol docs/solidity-101/14_Interface/InterfaceDemo.sol docs/solidity-102/18_Import/Import.sol docs/solidity-102/25_Create2/Create2.sol docs/solidity-102/26_DeleteContract/DeployContract.sol docs/solidity-102/26_DeleteContract/img/26-3.png docs/solidity-102/26_DeleteContract/img/26-4.png docs/solidity-102/26_DeleteContract/img/26-5.png docs/solidity-102/26_DeleteContract/img/26-6.png docs/solidity-103/39_Random/img/39-10.png docs/solidity-103/39_Random/img/39-6-1.png docs/solidity-103/39_Random/img/39-8.png docs/solidity-103/39_Random/img/39-9.png docs/solidity-103/51_ERC4626/ docs/solidity-103/52_EIP712/ docs/solidity-103/53_ERC20Permit/ docs/solidity-103/54_CrossChainBridge/ docs/solidity-103/55_MultiCall/ docs/solidity-103/56_DEX/ docs/solidity-103/57_Flashloan/ docs/solidity-104/S17_CrossReentrancy/
 
+--------------------------------
+Sync started at Sun Nov 24 01:14:01 UTC 2024
+
+
+Changes in docs/solidity-101:
+docs/solidity-101/02_ValueTypes/readme.md docs/solidity-101/03_Function/readme.md docs/solidity-101/04_Return/readme.md docs/solidity-101/05_DataStorage/readme.md docs/solidity-101/07_Mapping/readme.md docs/solidity-101/09_Constant/readme.md docs/solidity-101/10_InsertionSort/readme.md docs/solidity-101/12_Event/readme.md docs/solidity-101/13_Inheritance/Inheritance.sol docs/solidity-101/13_Inheritance/readme.md
+
+Changes in docs/solidity-102:
+docs/solidity-101/02_ValueTypes/readme.md docs/solidity-101/03_Function/readme.md docs/solidity-101/04_Return/readme.md docs/solidity-101/05_DataStorage/readme.md docs/solidity-101/07_Mapping/readme.md docs/solidity-101/09_Constant/readme.md docs/solidity-101/10_InsertionSort/readme.md docs/solidity-101/12_Event/readme.md docs/solidity-101/13_Inheritance/Inheritance.sol docs/solidity-101/13_Inheritance/readme.md docs/solidity-102/17_Library/readme.md docs/solidity-102/23_Delegatecall/readme.md docs/solidity-102/24_Create/readme.md docs/solidity-102/26_DeleteContract/readme.md docs/solidity-102/27_ABIEncode/readme.md docs/solidity-102/30_TryCatch/readme.md docs/solidity-102/24_Create/img/24-4.png
+
+Changes in docs/solidity-103:
+docs/solidity-101/02_ValueTypes/readme.md docs/solidity-101/03_Function/readme.md docs/solidity-101/04_Return/readme.md docs/solidity-101/05_DataStorage/readme.md docs/solidity-101/07_Mapping/readme.md docs/solidity-101/09_Constant/readme.md docs/solidity-101/10_InsertionSort/readme.md docs/solidity-101/12_Event/readme.md docs/solidity-101/13_Inheritance/Inheritance.sol docs/solidity-101/13_Inheritance/readme.md docs/solidity-102/17_Library/readme.md docs/solidity-102/23_Delegatecall/readme.md docs/solidity-102/24_Create/readme.md docs/solidity-102/26_DeleteContract/readme.md docs/solidity-102/27_ABIEncode/readme.md docs/solidity-102/30_TryCatch/readme.md docs/solidity-103/34_ERC721/ERC721.sol docs/solidity-103/34_ERC721/readme.md docs/solidity-103/35_DutchAuction/readme.md docs/solidity-103/36_MerkleTree/img/36-1.png docs/solidity-103/36_MerkleTree/img/36-2.png docs/solidity-103/36_MerkleTree/readme.md docs/solidity-103/37_Signature/readme.md docs/solidity-103/38_NFTSwap/NFTSwap.sol docs/solidity-103/38_NFTSwap/readme.md docs/solidity-103/40_ERC1155/ERC1155.sol docs/solidity-103/40_ERC1155/readme.md docs/solidity-103/46_ProxyContract/readme.md docs/solidity-103/47_Upgrade/readme.md docs/solidity-103/48_TransparentProxy/readme.md docs/solidity-103/49_UUPS/readme.md docs/solidity-103/50_MultisigWallet/MultisigWallet.sol docs/solidity-103/50_MultisigWallet/readme.md docs/solidity-103/51_ERC4626/readme.md docs/solidity-103/52_EIP712/readme.md docs/solidity-103/53_ERC20Permit/readme.md docs/solidity-103/54_CrossChainBridge/crosschain.js docs/solidity-103/54_CrossChainBridge/readme.md docs/solidity-103/56_DEX/readme.md docs/solidity-102/24_Create/img/24-4.png docs/solidity-103/56_DEX/img/56-10.jpg docs/solidity-103/56_DEX/img/56-11.jpg docs/solidity-103/56_DEX/img/56-2.jpg docs/solidity-103/56_DEX/img/56-3.jpg docs/solidity-103/56_DEX/img/56-4.jpg docs/solidity-103/56_DEX/img/56-5.jpg docs/solidity-103/56_DEX/img/56-6.jpg docs/solidity-103/56_DEX/img/56-7.jpg docs/solidity-103/56_DEX/img/56-8.jpg docs/solidity-103/56_DEX/img/56-9.jpg
+
+Changes in docs/solidity-104:
+docs/solidity-101/02_ValueTypes/readme.md docs/solidity-101/03_Function/readme.md docs/solidity-101/04_Return/readme.md docs/solidity-101/05_DataStorage/readme.md docs/solidity-101/07_Mapping/readme.md docs/solidity-101/09_Constant/readme.md docs/solidity-101/10_InsertionSort/readme.md docs/solidity-101/12_Event/readme.md docs/solidity-101/13_Inheritance/Inheritance.sol docs/solidity-101/13_Inheritance/readme.md docs/solidity-102/17_Library/readme.md docs/solidity-102/23_Delegatecall/readme.md docs/solidity-102/24_Create/readme.md docs/solidity-102/26_DeleteContract/readme.md docs/solidity-102/27_ABIEncode/readme.md docs/solidity-102/30_TryCatch/readme.md docs/solidity-103/34_ERC721/ERC721.sol docs/solidity-103/34_ERC721/readme.md docs/solidity-103/35_DutchAuction/readme.md docs/solidity-103/36_MerkleTree/img/36-1.png docs/solidity-103/36_MerkleTree/img/36-2.png docs/solidity-103/36_MerkleTree/readme.md docs/solidity-103/37_Signature/readme.md docs/solidity-103/38_NFTSwap/NFTSwap.sol docs/solidity-103/38_NFTSwap/readme.md docs/solidity-103/40_ERC1155/ERC1155.sol docs/solidity-103/40_ERC1155/readme.md docs/solidity-103/46_ProxyContract/readme.md docs/solidity-103/47_Upgrade/readme.md docs/solidity-103/48_TransparentProxy/readme.md docs/solidity-103/49_UUPS/readme.md docs/solidity-103/50_MultisigWallet/MultisigWallet.sol docs/solidity-103/50_MultisigWallet/readme.md docs/solidity-103/51_ERC4626/readme.md docs/solidity-103/52_EIP712/readme.md docs/solidity-103/53_ERC20Permit/readme.md docs/solidity-103/54_CrossChainBridge/crosschain.js docs/solidity-103/54_CrossChainBridge/readme.md docs/solidity-103/56_DEX/readme.md docs/solidity-104/S01_ReentrancyAttack/readme.md docs/solidity-104/S02_SelectorClash/SelectorClash.sol docs/solidity-104/S05_Overflow/readme.md docs/solidity-104/S06_SignatureReplay/readme.md docs/solidity-104/S08_ContractCheck/readme.md docs/solidity-104/S09_DoS/readme.md docs/solidity-104/S10_Honeypot/readme.md docs/solidity-104/S13_UncheckedCall/readme.md docs/solidity-104/S15_OracleManipulation/readme.md docs/solidity-104/S15_OracleManipulation/test/Oracle.t.sol docs/solidity-102/24_Create/img/24-4.png docs/solidity-103/56_DEX/img/56-10.jpg docs/solidity-103/56_DEX/img/56-11.jpg docs/solidity-103/56_DEX/img/56-2.jpg docs/solidity-103/56_DEX/img/56-3.jpg docs/solidity-103/56_DEX/img/56-4.jpg docs/solidity-103/56_DEX/img/56-5.jpg docs/solidity-103/56_DEX/img/56-6.jpg docs/solidity-103/56_DEX/img/56-7.jpg docs/solidity-103/56_DEX/img/56-8.jpg docs/solidity-103/56_DEX/img/56-9.jpg
+

docs/solidity-101/02_ValueTypes/readme.md

@@ -70,14 +70,14 @@ bool public _bool5 = _bool != _bool1; // 不相等
 ```solidity
 // 整型
 int public _int = -1; // 整数，包括负数
-uint public _uint = 1; // 正整数
-uint256 public _number = 20220330; // 256位正整数
+uint public _uint = 1; // 无符号整数
+uint256 public _number = 20220330; // 256位无符号整数
 ```
 
 常用的整型运算符包括：
 
 - 比较运算符（返回布尔值）： `<=`， `<`，`==`， `!=`， `>=`， `>`
-- 算数运算符： `+`， `-`， `*`， `/`， `%`（取余），`**`（幂）
+- 算术运算符： `+`， `-`， `*`， `/`， `%`（取余），`**`（幂）
 
 ```solidity
 // 整数运算
@@ -119,7 +119,7 @@ bytes32 public _byte32 = "MiniSolidity";
 bytes1 public _byte = _byte32[0]; 
 ```
 
-在上述代码中，`MiniSolidity` 变量以字节的方式存储进变量 `_byte32`。如果把它转换成 `16 进制`，就是：`0x4d696e69536f6c69646974790000000000000000000000000000000000000000`
+在上述代码中，字符串 `MiniSolidity` 以字节的方式存储进变量 `_byte32`。如果把它转换成 `16 进制`，就是：`0x4d696e69536f6c69646974790000000000000000000000000000000000000000`
 
 `_byte` 变量的值为 `_byte32` 的第一个字节，即 `0x4d`。
 
@@ -134,7 +134,7 @@ enum ActionSet { Buy, Hold, Sell }
 ActionSet action = ActionSet.Buy;
 ```
 
-枚举可以显式地和 `uint` 相互转换，并会检查转换的正整数是否在枚举的长度内，否则会报错：
+枚举可以显式地和 `uint` 相互转换，并会检查转换的无符号整数是否在枚举的长度内，否则会报错：
 
 ```solidity
 // enum可以和uint显式的转换
@@ -143,7 +143,7 @@ function enumToUint() external view returns(uint){
 }
 ```
 
-`enum` 是一个比较冷门的变量，几乎没什么人用。
+`enum` 是一个比较冷门的数据类型，几乎没什么人用。
 
 ## 在 Remix 上运行
 

docs/solidity-101/03_Function/readme.md

@@ -27,7 +27,8 @@ Solidity语言的函数非常灵活，可以进行各种复杂操作。在本教
 我们先看一下 Solidity 中函数的形式:
 
 ```solidity
-function <function name>(<parameter types>) {internal|external|public|private} [pure|view|payable] [returns (<return types>)]
+function <function name>([parameter types[, ...]]) {internal|external|public|private} [pure|view|payable] [virtual|override] [<modifiers>]
+[returns (<return types>)]{ <function body> }
 ```
 
 看着有一些复杂，让我们从前往后逐个解释(方括号中的是可写可不
@@ -37,7 +38,7 @@ function <function name>(<parameter types>) {internal|external|public|private} [
 
 2. `<function name>`：函数名。
 
-3. `(<parameter types>)`：圆括号内写入函数的参数，即输入到函数的变量类型和名称。
+3. `([parameter types[, ...]])`：圆括号内写入函数的参数，即输入到函数的变量类型和名称。
 
 4. `{internal|external|public|private}`：函数可见性说明符，共有4种。
 
@@ -48,11 +49,17 @@ function <function name>(<parameter types>) {internal|external|public|private} [
 
     **注意 1**：合约中定义的函数需要明确指定可见性，它们没有默认值。
 
-    **注意 2**：`public|private|internal` 也可用于修饰状态变量。`public`变量会自动生成同名的`getter`函数，用于查询数值。未标明可见性类型的状态变量，默认为`internal`。
+    **注意 2**：`public|private|internal` 也可用于修饰状态变量(定义可参考[WTF Solidity 第5讲的相关内容]([../05_DataStorage/readme.md#1-状态变量](https://github.com/AmazingAng/WTF-Solidity/tree/main/05_DataStorage#1-%E7%8A%B6%E6%80%81%E5%8F%98%E9%87%8F)))。`public`变量会自动生成同名的`getter`函数，用于查询数值。未标明可见性类型的状态变量，默认为`internal`。
 
 5. `[pure|view|payable]`：决定函数权限/功能的关键字。`payable`（可支付的）很好理解，带着它的函数，运行的时候可以给合约转入 ETH。`pure` 和 `view` 的介绍见下一节。
 
-6. `[returns ()]`：函数返回的变量类型和名称。
+6. `[virtual|override]`: 方法是否可以被重写，或者是否是重写方法。`virtual`用在父合约上，标识的方法可以被子合约重写。`override`用在自合约上，表名方法重写了父合约的方法。
+
+7. `<modifiers>`: 自定义的修饰器，可以有0个或多个修饰器。
+
+8. `[returns ()]`：函数返回的变量类型和名称。
+
+9. `<function body>`: 函数体。 
 
 ## 到底什么是 `Pure` 和`View`？