tienshaoku/swap.js

## swap.js
function swapETHToDai() public payable returns(uint[] memory) {
    // static array: address[k] memory array;
    // The following is the dynamic array way of initialization
    address[] memory _paths = new address[](2);
    // Also, push() is for storage array.
    _paths[0] = WETHAddress;
    _paths[1] = DaiAddress;
    return uniswapV2Router01.swapExactETHForTokens{value: msg.value}(0, _paths, msg.sender, now + 120);
}

function swapDaiForETH(uint _DaiAmount) public returns(uint[] memory) {
    require(Dai.transferFrom(msg.sender, address(this), _DaiAmount));
    address[] memory _paths = new address[](2);
    _paths[0] = DaiAddress;
    _paths[1] = WETHAddress;
    Dai.approve(address(uniswapV2Router01), _DaiAmount);
    return uniswapV2Router01.swapExactTokensForETH(_DaiAmount, 0, _paths, msg.sender, now + 120);
}
	function swapETHToDai() public payable returns(uint[] memory) {
	// static array: address[k] memory array;
	// The following is the dynamic array way of initialization
	address[] memory _paths = new address[](2);
	// Also, push() is for storage array.
	_paths[0] = WETHAddress;
	_paths[1] = DaiAddress;
	return uniswapV2Router01.swapExactETHForTokens{value: msg.value}(0, _paths, msg.sender, now + 120);
	}

	function swapDaiForETH(uint _DaiAmount) public returns(uint[] memory) {
	require(Dai.transferFrom(msg.sender, address(this), _DaiAmount));
	address[] memory _paths = new address[](2);
	_paths[0] = DaiAddress;
	_paths[1] = WETHAddress;
	Dai.approve(address(uniswapV2Router01), _DaiAmount);
	return uniswapV2Router01.swapExactTokensForETH(_DaiAmount, 0, _paths, msg.sender, now + 120);
	}