This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The Touch.identifier returns a value uniquely identifying this point of contact with the touch surface. This value remains consistent for every event involving this finger's (or stylus's) movement on the surface until it is lifted off the surface.
Syntax
touchItem.identifier;
Return value
A long that represents the unique ID of the Touch object.
Example
someElement.addEventListener('touchmove', function(e) {
// Iterate through the list of touch points that changed
// since the last event and print each touch point's identifier.
for (var i=0; i < e.changedTouches.length; i++) {
console.log("changedTouches[" + i + "].identifier = " + e.changedTouches[i].identifier);
}
}, false);
Specifications
| Specification | Status | Comment |
|---|---|---|
| Touch Events – Level 2 | Editor's Draft | No change. |
| Touch Events | Recommendation | Initial definition. |
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support | 22.0 | (Yes) | 18.0 (18.0)[1] 52.0 (52.0)[2] |
No support | No support | No support |
| Feature | Android | Android Webview | Chrome for Android | Edge | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | (Yes) | (Yes) | 6.0 (6.0) | (Yes) | 11 | (Yes) | (Yes) |
[1] Touch events were implemented in Gecko 18.0, but removed again in 24.0 (Firefox 24.0 / Thunderbird 24.0 / SeaMonkey 2.21) on the desktop version of Firefox due to web compatibility issues (bug 888304).
[2] As of Gecko 52.0, touch events support has been fixed and reenabled in Windows desktop platforms.