Uint256 的問題

這是我在這裡的第一篇文章，當我搜尋時我無法找到我的問題的答案。我正在使用帶有 Metamask 的 Remix，我創建了契約並使用以下程式碼進行鑄造。我在契約中有鑄造限制。但是，代幣向我顯示了總供應量為一個巨大的值“10000000000000000000”，這已經高於總供應量限制，因此對鑄幣的檢查會停止執行。

$$ ![enter image description here $$$$ 1 $$]$$ 1 $$

  function mint(uint noOfTokens) returns (bool) {
     checkTokens = _totalSupply.add(noOfTokens); 
  // Check the max limit and the owner before minting 
  require(_totalSupply <= maxLimit 
           && checkTokens <= maxLimit 
           && (msg.sender == address(owner)));
   balances[owner] = balances[owner].add(noOfTokens);
  _totalSupply        = _totalSupply.add(noOfTokens);
  return true;

}

變數定義為 uint256。

感謝您的幫助和支持。NKB。

$$ ![enter image description here $$$$ 2 $$]$$ 2 $$ pragma 可靠性 ^0.4.11;

//ERC20介面導入’./ERC20.sol’; // 高低攻擊的安全數學。導入’./SafeMath.sol';

contract Test is ERC20 { // 對 uint256 使用安全數學，對 uint256

使用 SafeMath；

uint256 public constant maxLimit = 500000000; 
uint256 public  _totalSupply = 0; 
string public constant symbol = "Test";
string public constant name = "TestCoin";
uint8 public constant decimals = 0;
// Rate -> 1 Ether = 1000 Just 
uint256 public RATE; 
// Ether reciever 
address public owner;
uint public start;
uint public startWeek;
uint public startTwoWeek;
uint public startFourWeek;
uint256 public tokens;
uint256 public checkTokens;

mapping(address=> uint256) balances; 
mapping(address=>mapping(address=>uint256)) allowed;


// Fallback function
// The function without name is the default function that is called 
// whenever anyone sends funds to a contract

function() payable{
   createTokens();
}

function Test(){
  // balances[msg.sender] = _totalSupply;
owner  = msg.sender;  // get the owner of the token
start  = now;  // Get the current block time 
startWeek = start + 30 minutes ; // Get the scond block time
startTwoWeek = start + 60 minutes; // Get the third block time 
startFourWeek = start + 90 minutes; // Get the fourth block time . 

}

// Create new tokens
  function mint(uint noOfTokens) returns (bool) {
     checkTokens = _totalSupply.add(noOfTokens); 
  // Check the max limit and the owner before minting 
  require(_totalSupply/1000000000000000000 <= maxLimit 
           && checkTokens/1000000000000000000 <= maxLimit 
           && (msg.sender == address(owner)));
   balances[owner] = balances[owner].add(noOfTokens);
  _totalSupply     = _totalSupply.add(noOfTokens);
  return true;

}

function createTokens() payable {
   require(msg.value >0 && _totalSupply <= maxLimit);

   if (now <= startWeek   && now > start) {
   RATE =    1150; 
   tokens = msg.value.mul(RATE);
   balances[msg.sender] = balances[msg.sender].add(tokens);
   _totalSupply = _totalSupply.add(tokens);
   owner.transfer(msg.value);
}

if (now <= startTwoWeek && now > startWeek ) {
   RATE =    1100;
   tokens = msg.value.mul(RATE);
   balances[msg.sender] = balances[msg.sender].add(tokens);
   _totalSupply = _totalSupply.add(tokens);
   owner.transfer(msg.value);
}

if (now <= startFourWeek && now > startTwoWeek ) {
   RATE =    1050;
   tokens = msg.value.mul(RATE);
   balances[msg.sender] = balances[msg.sender].add(tokens);
   _totalSupply = _totalSupply.add(tokens);
   owner.transfer(msg.value);
}
if (now > startFourWeek ) {
   RATE =    1000;
   tokens = msg.value.mul(RATE);
   balances[msg.sender] = balances[msg.sender].add(tokens);
   _totalSupply = _totalSupply.add(tokens);
   owner.transfer(msg.value);
}


}
 function totalSupply() constant returns (uint totalSupply){
     return _totalSupply;
 }

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

 function transfer(address _to, uint _value) returns (bool success){
     require( balances[msg.sender] >= _value &&
         _value > 0 );
         balances[msg.sender] = balances[msg.sender].sub(_value) ;
         balances[_to] = balances[_to].add(_value);
         Transfer(msg.sender,_to,_value);
         return true;
 }

 function transferFrom(address _from, address _to, uint _value) returns (bool success){
     require( allowed[_from][msg.sender] >= _value &&
     balances[_from] >= _value
     && _value > 0 );
   balances[_from]  = balances[_from].sub(_value);
   balances[_to]    = balances[_to].add(_value);
   allowed[_from][msg.sender]  = allowed[_from][msg.sender].sub(_value);
   Transfer(_from,_to,_value);
   return true;
 }

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

 }

 function allowance(address _owner, address _spender) constant returns (uint remaining){
   return allowed [_owner][_spender];  
 }
 event GoalReached(address beneficiary, uint amountRaised);
 event Transfer(address indexed _from, address indexed _to, uint _value);
 event Approval(address indexed _owner, address indexed _spender, uint _value);

}

即使令牌是用零小數定義的，它也會為 wei 選擇 18 位小數並將值與所有小數一起放入。

因為您**decimals設置為18，所以您必須除以*（1 後跟 18 個零）以獲得整數值1,000,000,000,000,000,000* _totalSupply.

18 位小數是乙太坊的標準。最小的單位被稱為一個Wei。1,000,000,000,000,000,000 wei 等於 1 Ether。這是一個單位地圖。

為了簡化您的契約，您可以將小數設置為**0，在這種情況下，您將只處理不可整除的整數值。不利的一面是，您不能再提供代幣的一部分。**

引用自：https://ethereum.stackexchange.com/questions/27999