IERC20.sol
View Source: contracts/tests/IERC20.sol
IERC20
Interface of the ERC20 standard as defined in the EIP. Does not include the optional functions; to access them see {ERC20Detailed}.
Transfer
Emitted when value tokens are moved from one account (from) to
another (to).
Note that value may be zero.
Parameters
| Name | Type | Description |
|---|---|---|
| from | address | |
| to | address | |
| value | uint256 |
Approval
Emitted when the allowance of a spender for an owner is set by
a call to {approve}. value is the new allowance.
Parameters
| Name | Type | Description |
|---|---|---|
| owner | address | |
| spender | address | |
| value | uint256 |
Functions
totalSupply
Returns the amount of tokens in existence.
function totalSupply() external view
returns(uint256)
Arguments
| Name | Type | Description |
|---|
balanceOf
Returns the amount of tokens owned by account.
function balanceOf(address account) external view
returns(uint256)
Arguments
| Name | Type | Description |
|---|---|---|
| account | address |
transfer
Moves amount tokens from the caller's account to recipient.
Returns a boolean value indicating whether the operation succeeded.
Emits a {Transfer} event.
function transfer(address recipient, uint256 amount) external nonpayable
returns(bool)
Arguments
| Name | Type | Description |
|---|---|---|
| recipient | address | |
| amount | uint256 |
allowance
Returns the remaining number of tokens that spender will be
allowed to spend on behalf of owner through {transferFrom}. This is
zero by default.
This value changes when {approve} or {transferFrom} are called.
function allowance(address owner, address spender) external view
returns(uint256)
Arguments
| Name | Type | Description |
|---|---|---|
| owner | address | |
| spender | address |
approve
Sets amount as the allowance of spender over the caller's tokens.
Returns a boolean value indicating whether the operation succeeded.
IMPORTANT: Beware that changing an allowance with this method brings the risk
that someone may use both the old and the new allowance by unfortunate
transaction ordering. One possible solution to mitigate this race
condition is to first reduce the spender's allowance to 0 and set the
desired value afterwards:
https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
Emits an {Approval} event.
function approve(address spender, uint256 amount) external nonpayable
returns(bool)
Arguments
| Name | Type | Description |
|---|---|---|
| spender | address | |
| amount | uint256 |
transferFrom
Moves amount tokens from sender to recipient using the
allowance mechanism. amount is then deducted from the caller's
allowance.
Returns a boolean value indicating whether the operation succeeded.
Emits a {Transfer} event.
function transferFrom(address sender, address recipient, uint256 amount) external nonpayable
returns(bool)
Arguments
| Name | Type | Description |
|---|---|---|
| sender | address | |
| recipient | address | |
| amount | uint256 |