---
title: num_layers
framework: accelerate
role: symbol
role_heading: Instance Property
path: accelerate/bnnslayerparameterslstm/num_layers
---

# num_layers

The number of stacked long short-term memory (LSTM) layers.

## Declaration

```swift
var num_layers: Int
```

## Discussion

Discussion If you define the corresponding array descriptor’s size to 0, BNNS uses this value. BNNS throws an error if you set this value to a nonzero value that doesn’t match the corresponding array descriptor’s size.

## See Also

### Instance Properties

- [input_size](accelerate/bnnslayerparameterslstm/input_size.md)
- [hidden_size](accelerate/bnnslayerparameterslstm/hidden_size.md)
- [batch_size](accelerate/bnnslayerparameterslstm/batch_size.md)
- [seq_len](accelerate/bnnslayerparameterslstm/seq_len.md)
- [dropout](accelerate/bnnslayerparameterslstm/dropout.md)
- [lstm_flags](accelerate/bnnslayerparameterslstm/lstm_flags.md)
- [sequence_descriptor](accelerate/bnnslayerparameterslstm/sequence_descriptor.md)
- [input_descriptor](accelerate/bnnslayerparameterslstm/input_descriptor.md)
- [output_descriptor](accelerate/bnnslayerparameterslstm/output_descriptor.md)
- [input_gate](accelerate/bnnslayerparameterslstm/input_gate.md)
- [forget_gate](accelerate/bnnslayerparameterslstm/forget_gate.md)
- [candidate_gate](accelerate/bnnslayerparameterslstm/candidate_gate.md)
- [output_gate](accelerate/bnnslayerparameterslstm/output_gate.md)
- [hidden_activation](accelerate/bnnslayerparameterslstm/hidden_activation.md)