# evm_iszero

Implements the EVM ISZERO opcode: returns BIGINT 1 when the complete UINT256 word is zero and 0 otherwise. NULL input propagates to NULL.

Canonical HTML: <https://determica.com/docs/functions/evm_iszero>

- Kind: scalar function
- Category: [EVM utilities](/docs/category/evm-utilities.md)
- Tags: Types, EVM

Implements the EVM ISZERO opcode: returns BIGINT 1 when the complete UINT256 word is zero and 0 otherwise. NULL input propagates to NULL.

## Overload 1: evm_iszero(UINT256)

```sql
evm_iszero(UINT256)
```

Returns 1 for a zero UINT256 input and 0 otherwise.

- Kind: scalar
- Execution context: Offline
- Behavior: Transform
- Execution modes: Offline
- Input shape: Scalar Arguments
- Planning contract: Runtime
- Cardinality: One Per Input
- Determinism: Deterministic
- Return shape: Scalar
- Schema stability: Fixed
- Stability: Stable
- Side effects: None documented

### Inputs

- `x` (UINT256; required; positional) — UINT256 word tested for zero.

### Returns

Zero indicator

BIGINT 1 or 0, or NULL for NULL input.

- `is_zero` (BIGINT)

Zero indicator. BIGINT 1 or 0, or NULL for NULL input.

### Examples

_Local SQL · Local_

```sql
SELECT evm_iszero(7::UINT256) AS result;
-- => [{"result":0}]
```