# envString

Description: envString 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-string.mdx

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

### Signature

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

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

### Description

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

### Tips

- For arrays, you can specify the delimiter used to separate the values with the `delimiter` parameter.
- Choose a delimiter that doesn't appear in the string values, so that they can be correctly separated.

### Examples

#### Single Value

With environment variable `STRING_VALUE=hello, world!`,

```solidity
string memory key = "STRING_VALUE";
string memory expected = "hello, world!";
string memory output = vm.envString(key);
assertEq(output, expected);
```

#### Array

With environment variable `STRING_VALUES=hello, world!|0x7109709ECfa91a80626fF3989D68f67F5b1DD12D`;

```solidity
string memory key = "STRING_VALUES";
string memory delimiter = "|";
string[2] memory expected = [
    "hello, world!",
    "0x7109709ECfa91a80626fF3989D68f67F5b1DD12D"
];
string[] memory output = vm.envString(key, delimiter);
for (uint i = 0; i < expected.length; ++i) {
    assert(keccak256(abi.encodePacked((output[i]))) == keccak256(abi.encodePacked((expected[i]))));
}
```