IERC20Upgradeable
Interface of the ERC20 standard as defined in the EIP.
Methods
allowance
function allowance(address owner, address spender) external view returns (uint256)
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.
Parameters
| Name | Type | Description |
|---|---|---|
| owner | address | undefined |
| spender | address | undefined |
Returns
| Name | Type | Description |
|---|---|---|
| _0 | uint256 | undefined |
approve
function approve(address spender, uint256 amount) external nonpayable returns (bool)
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.
Parameters
| Name | Type | Description |
|---|---|---|
| spender | address | undefined |
| amount | uint256 | undefined |
Returns
| Name | Type | Description |
|---|---|---|
| _0 | bool | undefined |
balanceOf
function balanceOf(address account) external view returns (uint256)
Returns the amount of tokens owned by account.
Parameters
| Name | Type | Description |
|---|---|---|
| account | address | undefined |
Returns
| Name | Type | Description |
|---|---|---|
| _0 | uint256 | undefined |
totalSupply
function totalSupply() external view returns (uint256)
Returns the amount of tokens in existence.
Returns
| Name | Type | Description |
|---|---|---|
| _0 | uint256 | undefined |
transfer
function transfer(address to, uint256 amount) external nonpayable returns (bool)
Moves amount tokens from the caller's account to to. Returns a boolean value indicating whether the operation succeeded. Emits a {Transfer} event.
Parameters
| Name | Type | Description |
|---|---|---|
| to | address | undefined |
| amount | uint256 | undefined |
Returns
| Name | Type | Description |
|---|---|---|
| _0 | bool | undefined |
transferFrom
function transferFrom(address from, address to, uint256 amount) external nonpayable returns (bool)
Moves amount tokens from from to to 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.
Parameters
| Name | Type | Description |
|---|---|---|
| from | address | undefined |
| to | address | undefined |
| amount | uint256 | undefined |
Returns
| Name | Type | Description |
|---|---|---|
| _0 | bool | undefined |
Events
Approval
event Approval(address indexed owner, address indexed spender, uint256 value)
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 indexed | address | undefined |
spender indexed | address | undefined |
| value | uint256 | undefined |
Transfer
event Transfer(address indexed from, address indexed to, uint256 value)
Emitted when value tokens are moved from one account (from) to another (to). Note that value may be zero.
Parameters
| Name | Type | Description |
|---|---|---|
from indexed | address | undefined |
to indexed | address | undefined |
| value | uint256 | undefined |