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## `rollSlot`

### Signature

```solidity
function rollSlot(uint64 newSlotNumber) external;
```

### Description

Sets `block.slotnum` to the specified value.

The slot number is independent of the block number and timestamp. Calling `rollSlot` does not change either value. You can move the slot number forwards or backwards, including to zero. Use [`vm.getSlotNumber()`](/reference/cheatcodes/get-slot-number) to read it after an update, because the compiler may optimize repeated `block.slotnum` reads away.

Requires the Amsterdam EVM hardfork or later and reverts on earlier versions. Slot numbers are unsigned 64-bit values, as defined by [EIP-7843](https://eips.ethereum.org/EIPS/eip-7843).

### Parameters

| Parameter | Type | Description |
|-----------|------|-------------|
| `newSlotNumber` | `uint64` | The new slot number, from 0 to 2^64 − 1 |

Solidity exposes `block.slotnum` starting with version 0.8.37.

### Examples

With `evm_version = "amsterdam"` configured:

```solidity [test/SlotNumber.t.sol]
function testSlotNumber() public {
    uint256 number = vm.getBlockNumber();
    uint256 timestamp = vm.getBlockTimestamp();

    vm.rollSlot(100);
    assertEq(vm.getSlotNumber(), 100);
    vm.rollSlot(101);
    assertEq(vm.getSlotNumber(), 101);

    assertEq(vm.getBlockNumber(), number);
    assertEq(vm.getBlockTimestamp(), timestamp);
}
```

### Related Cheatcodes

* [`getSlotNumber`](/reference/cheatcodes/get-slot-number) - Gets the current slot number
* [`roll`](/reference/cheatcodes/roll) - Sets the block number
* [`warp`](/reference/cheatcodes/warp) - Sets the timestamp