未聲明的標識符“餘額”

如何修復balances[msg.sender] = 1000000000000000000000000000; 以下程式碼中未聲明的標識符

pragma solidity ^0.4.4;

contract Token {

   /// @return total amount of tokens
   function totalSupply() constant returns (uint256 supply) {}

   /// @param _owner The address from which the balance will be retrieved
   /// @return The balance
   function balanceOf(address _owner) constant returns (uint256 balance) {}

   /// @notice send `_value` token to `_to` from `msg.sender`
   /// @param _to The address of the recipient
   /// @param _value The amount of token to be transferred
   /// @return Whether the transfer was successful or not
   function transfer(address _to, uint256 _value) returns (bool success) {}

   /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
   /// @param _from The address of the sender
   /// @param _to The address of the recipient
   /// @param _value The amount of token to be transferred
   /// @return Whether the transfer was successful or not
   function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}

   /// @notice `msg.sender` approves `_addr` to spend `_value` tokens
   /// @param _spender The address of the account able to transfer the tokens
   /// @param _value The amount of wei to be approved for transfer
   /// @return Whether the approval was successful or not
   function approve(address _spender, uint256 _value) returns (bool success) {}

   /// @param _owner The address of the account owning tokens
   /// @param _spender The address of the account able to transfer the tokens
   /// @return Amount of remaining tokens allowed to spent
   function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}

   event Transfer(address indexed _from, address indexed _to, uint256 _value);
   event Approval(address indexed _owner, address indexed _spender, uint256 _value);

}

contract StandardToken {

   function transfer(address _to, uint256 _value) returns (bool success) {
       //Default assumes totalSupply can't be over max (2^256 - 1).
       //If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.
       //Replace the if with this one instead.
       //if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
       if (balances[msg.sender] >= _value && _value > 0) {
           balances[msg.sender] -= _value;
           balances[_to] += _value;
           transfer(msg.sender, _to, _value);
           return true;
       } else { return false; }
   }

   function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
       //same as above. Replace this line with the following if you want to protect against wrapping uints.
       //if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
       if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
           balances[_to] += _value;
           balances[_from] -= _value;
           allowed[_from][msg.sender] -= _value;
           transfer(_from, _to, _value);
           return true;
       } else { return false; }
   }

   function balanceOf(address _owner) constant returns (uint256 balance) {
       return balances[_owner];
   }

   function approve(address _spender, uint256 _value) returns (bool success) {
       allowed[msg.sender][_spender] = _value;
       approve(msg.sender, _spender, _value);
       return true;
   }

   function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
     return allowed[_owner][_spender];
   }

   mapping (address => uint256) balances;
   mapping (address => mapping (address => uint256)) allowed;
   uint256 public totalSupply;
}

contract NMR { // CHANGE THIS. Update the contract name.

   /* Public variables of the token */

   /*
   NOTE:
   The following variables are OPTIONAL vanities. One does not have to include them.
   They allow one to customise the token contract & in no way influences the core functionality.
   Some wallets/interfaces might not even bother to look at this information.
   */
   string public name;                   // Token Name
   uint8 public decimals;                // How many decimals to show. To be standard complicant keep it 18
   string public symbol;                 // An identifier: eg SBX, XPR etc..
   string public version = 'H1.0'; 
   uint256 public unitsOneEthCanBuy;     // How many units of your coin can be bought by 1 ETH?
   uint256 public totalEthInWei;         // WEI is the smallest unit of ETH (the equivalent of cent in USD or satoshi in BTC). We'll store the total ETH raised via our ICO here.  
   address public fundsWallet;           // Where should the raised ETH go?



   // This is a constructor function 
   // which means the following function name has to match the contract name declared above
   function NMRToken() {
       balances[msg.sender] = 1000000000000000000000000000;    // Give the creator all initial tokens. This is set to 1000 for example. If you want your initial tokens to be X and your decimal is 5, set this value to X * 100000. (CHANGE THIS)
       totalSupply = 1000000000000000000000000000;                        // Update total supply (1000 for example) (CHANGE THIS)
       name = "NMRToken";                                   // Set the name for display purposes (CHANGE THIS)
       decimals = 18;                                               // Amount of decimals for display purposes (CHANGE THIS)
       symbol = "NMR";                                             // Set the symbol for display purposes (CHANGE THIS)
       unitsOneEthCanBuy = 10000;                                      // Set the price of your token for the ICO (CHANGE THIS)
       fundsWallet = msg.sender;                                    // The owner of the contract gets ETH
   }

   function() payable{
       totalEthInWei = totalEthInWei + msg.value;
       uint256 amount = msg.value * unitsOneEthCanBuy;
       require(balances[fundsWallet] >= amount);

       balances[fundsWallet] = balances[fundsWallet] - amount;
       balances[msg.sender] = balances[msg.sender] + amount;

       Transfer(fundsWallet, msg.sender, amount); // Broadcast a message to the blockchain

       //Transfer ether to fundsWallet
       fundsWallet.transfer(msg.value);                               
   }

   /* Approves and then calls the receiving contract */
   function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
       allowed[msg.sender][_spender] = _value;
       Approval(msg.sender, _spender, _value);

       //call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.
       //receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)
       //it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.
       if(!_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData)) { require; }
       return true;
   }
}

我假設您在（至少）StandardToken契約中遇到錯誤？該契約沒有這樣的變數。你可能應該從其他一些基本的代幣合約繼承——你展示的合約都沒有聲明這樣的標識符，所以很難說你應該繼承什麼。

男士：請停止建構您自己無法編寫的“繼承”契約。你必須控制你的程式碼，而不是嘗試和詢問直到它工作！

如果編譯器告訴你你正在使用的某些元素沒有聲明，這意味著它沒有聲明，或者聲明它有一些小的拼寫差異（“balance”而不是“balances”等等），或者它是在程式碼片段範圍之外聲明。

你要做的是：

1）檢查你的程式碼並找到聲明 2）如果它存在，檢查拼寫 3）如果它存在並且拼寫正確，檢查它是否對產生錯誤的程式碼片段可見 4）如果它不存在，聲明它

句點。沒有更簡單的了。

在這種情況下

   mapping (address => uint256) balances;

在 StandardToken 中聲明，但您不繼承它。所以它超出了程式碼片段的範圍！

這裡有兩個虛擬合約的原因是什麼？他們被單獨留下…

請檢查 Solidity 文件中的運算符“is”。

引用自：https://ethereum.stackexchange.com/questions/58975