WETH9 v0.2.1 API Reference
WETH9
WETH9 implements the Wrapped Ether (WETH) token standard. This contract allows users to wrap ETH into an ERC20-compatible token and unwrap it back to ETH.
Events
Approval
event Approval(address indexed src, address indexed guy, uint256 wad)
Emitted when an approval is set.
| Parameter | Type | Description |
|---|---|---|
| src | address | The address giving approval (indexed) |
| guy | address | The address receiving approval (indexed) |
| wad | uint256 | The amount of tokens approved |
Deposit
event Deposit(address indexed dst, uint256 wad)
Emitted when ETH is wrapped to WETH.
| Parameter | Type | Description |
|---|---|---|
| dst | address | The address receiving WETH (indexed) |
| wad | uint256 | The amount of ETH wrapped |
Transfer
event Transfer(address indexed src, address indexed dst, uint256 wad)
Emitted when tokens are transferred.
| Parameter | Type | Description |
|---|---|---|
| src | address | The sender's address (indexed) |
| dst | address | The recipient's address (indexed) |
| wad | uint256 | The amount of tokens transferred |
Withdrawal
event Withdrawal(address indexed src, uint256 wad)
Emitted when WETH is unwrapped back to ETH.
| Parameter | Type | Description |
|---|---|---|
| src | address | The address unwrapping WETH (indexed) |
| wad | uint256 | The amount of WETH unwrapped |
Variables
allowance
mapping(address => mapping(address => uint256)) public allowance
Maps owner addresses to spender addresses to approved amounts.
balanceOf
mapping(address => uint256) public balanceOf
Maps addresses to their token balances.
decimals
uint8 public decimals = 18
The number of decimal places used by the token.
name
string public name = "Wrapped Ether"
The name of the token.
symbol
string public symbol = "WETH"
The symbol of the token.
Functions
_deposit
function _deposit() internal
Internal function to handle ETH deposits and mint corresponding WETH tokens.
approve
function approve(address guy, uint256 wad) public returns (bool)
Approves another address to spend tokens.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| guy | address | The address to approve |
| wad | uint256 | The amount of tokens to approve |
Returns:
| Type | Description |
|---|---|
bool | Always returns true |
deposit
function deposit() external payable
Deposits ETH and mints WETH tokens.
receive
receive() external payable
Fallback function to handle direct ETH transfers. Calls _deposit() to wrap received ETH into WETH.
totalSupply
function totalSupply() public view returns (uint256)
Returns the total supply of WETH tokens.
Returns:
| Type | Description |
|---|---|
uint256 | The total amount of WETH in the contract |
transfer
function transfer(address dst, uint256 wad) public returns (bool)
Transfers tokens to another address.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| dst | address | The recipient's address |
| wad | uint256 | The amount of tokens to transfer |
Returns:
| Type | Description |
|---|---|
bool | True if the transfer succeeded |
transferFrom
function transferFrom(address src, address dst, uint256 wad) public returns (bool)
Transfers tokens from one address to another.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| src | address | The source address |
| dst | address | The destination address |
| wad | uint256 | The amount of tokens to transfer |
Returns:
| Type | Description |
|---|---|
bool | True if the transfer succeeded |
withdraw
function withdraw(uint256 wad) external
Withdraws ETH by burning WETH tokens.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| wad | uint256 | The amount to withdraw |