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Assessment.sol
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Assessment.sol
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// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
contract MyToken is IERC20, Ownable {
using SafeMath for uint256;
string public name;
string public symbol;
uint8 public decimals;
uint256 private _totalSupply;
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
constructor(string memory _name, string memory _symbol, uint8 _decimals, uint256 initialSupply, address initialOwner) Ownable(initialOwner) {
name = _name;
symbol = _symbol;
decimals = _decimals;
_totalSupply = initialSupply * 10 ** uint256(_decimals);
_balances[msg.sender] = _totalSupply;
emit Transfer(address(0), msg.sender, _totalSupply);
}
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
function balanceOf(address account) public view override returns (uint256) {
return _balances[account];
}
function transfer(address recipient, uint256 amount) public override returns (bool) {
_transfer(msg.sender, recipient, amount);
return true;
}
function allowance(address owner, address spender) public view override returns (uint256) {
return _allowances[owner][spender];
}
function approve(address spender, uint256 amount) public override returns (bool) {
_approve(msg.sender, spender, amount);
return true;
}
function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
function _transfer(address sender, address recipient, uint256 amount) internal {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
function _approve(address owner, address spender, uint256 amount) internal {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
function mint(address account, uint256 amount) public onlyOwner {
_mint(account, amount);
}
function _mint(address account, uint256 amount) internal {
require(account != address(0), "ERC20: mint to the zero address");
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
}