> ## Documentation Index
> Fetch the complete documentation index at: https://voltaire.tevm.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# jumpDests()

> Find all valid JUMPDEST positions in EVM bytecode

<Card title="Try it Live" icon="play" href="https://playground.tevm.sh?example=primitives/opcode.ts">
  Run Opcode examples in the interactive playground
</Card>

## Opcode.jumpDests()

Find all valid JUMPDEST positions in bytecode.

<Tabs>
  <Tab title="Functional API">
    ```typescript theme={null}
    import { jumpDests } from 'tevm/Opcode'

    const dests = jumpDests(bytecode)
    console.log(Array(dests))  // [3]
    ```
  </Tab>
</Tabs>

## Parameters

* `bytecode: Uint8Array` - Contract bytecode

## Returns

`Set<number>` - Set of valid JUMPDEST offsets

## Behavior

* **Correctly skips PUSH data**: JUMPDEST inside PUSH immediate bytes is NOT valid
* **Only JUMPDEST opcodes**: Only returns positions where opcode is 0x5B
* **Empty if none found**: Returns empty Set if no JUMPDESTs

## Use Cases

### Build Jump Table

```typescript theme={null}
function buildJumpTable(bytecode: Uint8Array): Map<number, string> {
  const dests = Opcode.jumpDests(bytecode)
  const table = new Map<number, string>()

  for (const offset of dests) {
    table.set(offset, `JUMPDEST_${offset.toString(16)}`)
  }

  return table
}
```

### Validate Jump Target

```typescript theme={null}
function isValidJumpTarget(bytecode: Uint8Array, target: number): boolean {
  const validDests = Opcode.jumpDests(bytecode)
  return validDests.has(target)
}
```

### Count Jump Destinations

```typescript theme={null}
function countJumpDests(bytecode: Uint8Array): number {
  return Opcode.jumpDests(bytecode).size
}
```

## Related

* [isValidJumpDest()](/primitives/opcode/is-valid-jump-dest) - Check specific offset
* [parse()](/primitives/opcode/parse) - Parse bytecode
* [isJump()](/primitives/opcode/is-jump) - Check if JUMP/JUMPI