# envUint

Description: envUint cheatcode documentation

Note: This document was authored using MDX

  Source: https://github.com/NomicFoundation/hardhat-website/tree/main/src/content/docs/docs/reference/cheatcodes/External/env-uint.mdx

{/* This document contains content copied/adapted from the Foundry Book (MIT licensed). See LICENSE in the parent directory. */}

### Signature

```solidity
function envUint(string calldata key) external returns (uint256 value);
```

```solidity
function envUint(
  string calldata key,
  string calldata delimiter
) external returns (uint256[] memory values);
```

### Description

Read an environment variable as `uint256` or `uint256[]`.

### Tips

- If the value starts with `0x`, it will be interpreted as a hex value, otherwise, it will be
  treated as a decimal number.
- For arrays, you can specify the delimiter used to separate the values with the `delimiter` parameter.

### Examples

#### Single Value

With environment variable `UINT_VALUE=115792089237316195423570985008687907853269984665640564039457584007913129639935`,

```solidity
string memory key = "UINT_VALUE";
uint256 expected = type(uint256).max;
uint256 output = cheats.envUint(key);
assert(output == expected);
```

#### Array

With environment variable `UINT_VALUES=0,0x0000000000000000000000000000000000000000000000000000000000000000`,

```solidity
string memory key = "UINT_VALUES";
string memory delimiter = ",";
uint256[2] memory expected = [type(uint256).min, type(uint256).min];
uint256[] memory output = cheats.envUint(key, delimiter);
assert(keccak256(abi.encodePacked((output))) == keccak256(abi.encodePacked((expected))));
```