IERC20

Interface of the ERC20 standard as defined in the EIP.

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.