I have just created an ERC20 Token; i set the decimal to 4 and bonus value to 1200 then i sent 0.3 ether to its contract address to purchase my new tokens. I received 36 quadrillion tokens in return and i don't understand why! before ETH network i have created a same contract at ROPSTEN testnet but with 18 decimals and i got 360 Tokens in return of 0.3 ether
I have these two questions: (a) what is the math here why i got quadrillions at network ETH? (b) can i convert tokens back to ether as a sender or as a contract owner? if yes how?
i have also tried sending tokens from myetherwallet but it is showing 0 of my tokens but i can see tokens under my address at both etherscan and ethplorer.io
contract code:
function constructorfunc() public {
symbol = "TKN";
name = "token name";
decimals = 4;
bonusEnds = now + 1 weeks;
endDate = now + 7 weeks;
}
function () public payable {
require(now >= startDate && now <= endDate);
uint tokens;
if (now <= bonusEnds) {
tokens = msg.value * 1200;
} else {
tokens = msg.value * 1000;
}
balances[msg.sender] = safeAdd(balances[msg.sender], tokens);
_totalSupply = safeAdd(_totalSupply, tokens);
Transfer(address(0), msg.sender, tokens);
owner.transfer(msg.value);
}
other functions that i have added in my contract
// ------------------------------------------------------------------------
// Total supply
// ------------------------------------------------------------------------
function totalSupply() public constant returns (uint) {
return _totalSupply - balances[address(0)];
}
// ------------------------------------------------------------------------
// Get the token balance for account `tokenOwner`
// ------------------------------------------------------------------------
function balanceOf(address tokenOwner) public constant returns (uint balance) {
return balances[tokenOwner];
}
// ------------------------------------------------------------------------
// Transfer the balance from token owner's account to `to` account
// - Owner's account must have sufficient balance to transfer
// - 0 value transfers are allowed
// ------------------------------------------------------------------------
function transfer(address to, uint tokens) public returns (bool success) {
balances[msg.sender] = safeSub(balances[msg.sender], tokens);
balances[to] = safeAdd(balances[to], tokens);
Transfer(msg.sender, to, tokens);
return true;
}
// ------------------------------------------------------------------------
// Token owner can approve for `spender` to transferFrom(...) `tokens`
// from the token owner's account
//
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
// recommends that there are no checks for the approval double-spend attack
// as this should be implemented in user interfaces
// ------------------------------------------------------------------------
function approve(address spender, uint tokens) public returns (bool success) {
allowed[msg.sender][spender] = tokens;
Approval(msg.sender, spender, tokens);
return true;
}
// ------------------------------------------------------------------------
// Transfer `tokens` from the `from` account to the `to` account
//
// The calling account must already have sufficient tokens approve(...)-d
// for spending from the `from` account and
// - From account must have sufficient balance to transfer
// - Spender must have sufficient allowance to transfer
// - 0 value transfers are allowed
// ------------------------------------------------------------------------
function transferFrom(address from, address to, uint tokens) public returns (bool success) {
balances[from] = safeSub(balances[from], tokens);
allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens);
balances[to] = safeAdd(balances[to], tokens);
Transfer(from, to, tokens);
return true;
}
// ------------------------------------------------------------------------
// Returns the amount of tokens approved by the owner that can be
// transferred to the spender's account
// ------------------------------------------------------------------------
function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
return allowed[tokenOwner][spender];
}
// ------------------------------------------------------------------------
// Token owner can approve for `spender` to transferFrom(...) `tokens`
// from the token owner's account. The `spender` contract function
// `receiveApproval(...)` is then executed
// ------------------------------------------------------------------------
function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) {
allowed[msg.sender][spender] = tokens;
Approval(msg.sender, spender, tokens);
ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data);
return true;
}