Contract Source Code:
File 1 of 1 : KCToken
pragma solidity >=0.4.22 <0.7.0;
interface tokenRecipient {
function receiveApproval(address _from, uint256 _value, address _token, bytes calldata _extraData) external;
}
contract KCToken {
// Public variables of the token
string public name;
string public symbol;
uint8 public decimals = 18;
// 18 decimals is the strongly suggested default, avoid changing it
uint256 public totalSupply;
address public owner;
// This creates an array with all balances
mapping(address => uint256) public balanceOf;
mapping(address => mapping(address => uint256)) public allowance;
// This generates a public event on the blockchain that will notify clients
event Transfer(address indexed from, address indexed to, uint256 value);
// This generates a public event on the blockchain that will notify clients
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
/**
* Constructor function
*
* Initializes contract with initial supply tokens to the creator of the contract
*/
constructor(
uint256 initialSupply,
string memory tokenName,
string memory tokenSymbol
) public {
totalSupply = initialSupply * 10 ** uint256(decimals);
// Update total supply with the decimal amount
balanceOf[msg.sender] = totalSupply;
// Give the creator all initial tokens
name = tokenName;
// Set the name for display purposes
symbol = tokenSymbol;
// Set the symbol for display purposes
owner = msg.sender;
}
function safeMul(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a * b;
assert(a == 0 || c / a == b);
return c;
}
function safeDiv(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b > 0);
uint256 c = a / b;
assert(a == b * c + a % b);
return c;
}
function safeSub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
function safeAdd(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(c >= a && c >= b);
return c;
}
/**
* Internal transfer, only can be called by this contract
*/
function _transfer(address _from, address _to, uint _value) internal {
// Prevent transfer to 0x0 address. Use burn() instead
require(_to != address(0x0));
// Check if the sender has enough
require(balanceOf[_from] >= _value);
// Check for overflows
require(balanceOf[_to] + _value >= balanceOf[_to]);
// Save this for an assertion in the future
uint previousBalances = balanceOf[_from] + balanceOf[_to];
// Subtract from the sender
balanceOf[_from] -= _value;
// Add the same to the recipient
balanceOf[_to] += _value;
emit Transfer(_from, _to, _value);
// Asserts are used to use static analysis to find bugs in your code. They should never fail
assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
}
/**
* Transfer tokens
*
* Send `_value` tokens to `_to` from your account
*
* @param _to The address of the recipient
* @param _value the amount to send
*/
function transfer(address _to, uint256 _value) public returns (bool success) {
_transfer(msg.sender, _to, _value);
return true;
}
/**
* Transfer tokens from other address
*
* Send `_value` tokens to `_to` on behalf of `_from`
*
* @param _from The address of the sender
* @param _to The address of the recipient
* @param _value the amount to send
*/
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
require(_value <= allowance[_from][msg.sender]);
// Check allowance
allowance[_from][msg.sender] -= _value;
_transfer(_from, _to, _value);
return true;
}
/**
* Set allowance for other address
*
* Allows `_spender` to spend no more than `_value` tokens on your behalf
*
* @param _spender The address authorized to spend
* @param _value the max amount they can spend
*/
function approve(address _spender, uint256 _value) public
returns (bool success) {
allowance[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
/**
* Set allowance for other address and notify
*
* Allows `_spender` to spend no more than `_value` tokens on your behalf, and then ping the contract about it
*
* @param _spender The address authorized to spend
* @param _value the max amount they can spend
* @param _extraData some extra information to send to the approved contract
*/
function approveAndCall(address _spender, uint256 _value, bytes memory _extraData)
public
returns (bool success) {
tokenRecipient spender = tokenRecipient(_spender);
if (approve(_spender, _value)) {
spender.receiveApproval(msg.sender, _value, address(this), _extraData);
return true;
}
}
//Transfer of ownership,only owner can call this function
function transferOwnership(address _address) public returns (bool success){
require((msg.sender == owner));
_transfer(owner, _address, balanceOf[owner]);
owner = _address;
return true;
}
}