IERC20
Interface of the ERC20 standard as defined in the EIP.
name
function name() external view returns (string)
symbol
function symbol() external view returns (string)
decimals
function decimals() external view returns (uint8)
totalSupply
function totalSupply() external view returns (uint256)
Returns the amount of tokens in existence.
balanceOf
function balanceOf(address account) external view returns (uint256)
Returns the amount of tokens owned by account
.
transfer
function transfer(address recipient, uint256 amount) external returns (bool)
_Moves amount
tokens from the caller's account to recipient
.
Returns a boolean value indicating whether the operation succeeded.
Emits a {Transfer} event._
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._
approve
function approve(address spender, uint256 amount) external 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._
transferFrom
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool)
_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._
Transfer
event Transfer(address from, address to, uint256 value)
_Emitted when value
tokens are moved from one account (from
) to
another (to
).
Note that value
may be zero._
Approval
event Approval(address owner, address 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.