# Library

## Code

[`UniswapV2Library.sol`](https://github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/libraries/UniswapV2Library.sol)

## Internal Functions

### sortTokens

```solidity
function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1);
```

Sorts token addresses.

### pairFor

```solidity
function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair);
```

Calculates the address for a pair without making any external calls (see Pair Addresses).

### getReserves

```solidity
function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB);
```

Calls getReserves on the pair for the passed tokens, and returns the results sorted in the order that the parameters were passed in.

### quote

```solidity
function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB);
```

Given some asset amount and reserves, returns an amount of the other asset representing equivalent value.

* Useful for calculating optimal token amounts before calling mint.

### getAmountOut

```solidity
function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut);
```

Given an *input* asset amount, returns the maximum *output* amount of the other asset (accounting for fees) given reserves.

* Used in [getAmountsOut](broken://pages/iAVxMCCpvWZ9JQIDWZa0).

### getAmountIn

```solidity
function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn);
```

Returns the minimum *input* asset amount required to buy the given *output* asset amount (accounting for fees) given reserves.

* Used in [getAmountsIn](broken://pages/iAVxMCCpvWZ9JQIDWZa0).

### getAmountsOut

```solidity
function getAmountsOut(uint amountIn, address[] memory path) internal view returns (uint[] memory amounts);
```

Given an *input* asset amount and an array of token addresses, calculates all subsequent maximum *output* token amounts by calling [getReserves](broken://pages/iAVxMCCpvWZ9JQIDWZa0) for each pair of token addresses in the path in turn, and using these to call [getAmountOut](broken://pages/iAVxMCCpvWZ9JQIDWZa0).

* Useful for calculating optimal token amounts before calling swap.

### getAmountsIn

```solidity
function getAmountsIn(uint amountOut, address[] memory path) internal view returns (uint[] memory amounts);
```

Given an *output* asset amount and an array of token addresses, calculates all preceding minimum *input* token amounts by calling [getReserves](broken://pages/iAVxMCCpvWZ9JQIDWZa0) for each pair of token addresses in the path in turn, and using these to call [getAmountIn](broken://pages/iAVxMCCpvWZ9JQIDWZa0).

* Useful for calculating optimal token amounts before calling swap.


---

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