---
title: attackTime
framework: corehaptics
role: symbol
role_heading: Type Property
path: corehaptics/chhapticevent/parameterid/attacktime
---

# attackTime

The time at which a haptic pattern’s intensity begins increasing.

## Declaration

```swift
static let attackTime: CHHapticEvent.ParameterID
```

## Discussion

Discussion This parameter can be an event parameter or a dynamic parameter. An event parameter indicates that the haptic begins increasing in intensity at the set time, where time 0 indicates now, or the current time. A dynamic value indicates that the time at which ramp-up begins can change. For example, a value of 0 indicates that the attack time is at its default value. Positive values up to 1.0 increase the attack time exponentially, while negative values down to -1.0 decrease the attack time exponentially. Haptic intensity responds to this parameter.

## See Also

### Haptic Event Parameter IDs

- [hapticIntensity](corehaptics/chhapticevent/parameterid/hapticintensity.md)
- [hapticSharpness](corehaptics/chhapticevent/parameterid/hapticsharpness.md)
- [decayTime](corehaptics/chhapticevent/parameterid/decaytime.md)
- [releaseTime](corehaptics/chhapticevent/parameterid/releasetime.md)
- [sustained](corehaptics/chhapticevent/parameterid/sustained.md)