> For the complete documentation index, see [llms.txt](https://ret2basic.gitbook.io/ctfnote/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ret2basic.gitbook.io/ctfnote/web3-security-research/foundry/console-log.md).
# Console Log
We can use `console.log()` to print out debugging info in Foundry just like in JavaScript. Import the following library:
```solidity
import "forge-std/console.sol";
```
Use `console.log()` in contract:
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;
import "forge-std/console.sol";
contract Counter {
uint public count;
// Function to get the current count
function get() public view returns (uint) {
return count;
}
// Function to increment count by 1
function inc() public {
console.log("Calling inc(). Now count = ", count);
count += 1;
}
// Function to decrement count by 1
function dec() public {
// This function will fail if count = 0
count -= 1;
}
}
```
Verbosity at least `-vv` must be used to print out `console.log()` messages:
```bash
forge test --match-path test/Counter.t.sol -vv
```
console.log() in contract
Of course you can also use `console.log()` in test file. For example, create a test file `Console.t.sol`:
```solidity
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;
import "forge-std/Test.sol";
contract ConsoleTest is Test {
function testLogSomething() view public {
console.log("Log something here", 123);
}
}
```
No need to import `forge-std/console.sol` because it is included in `forge-std/Test.sol`, which is already imported.
Run test with `-vv` verbosity:
```bash
forge test --match-path test/Console.t.sol -vv
```
console.log() in test file
One caveat here: `console.log()` can not log `int`. There is another function named `console.logInt()` for doing this job:
```solidity
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;
import "forge-std/Test.sol";
contract ConsoleTest is Test {
function testLogSomething() view public {
console.log("Log something here", 123);
int x = -1;
console.logInt(x);
}
}
```
