XRInputSourceArray.keys() - Web APIs 编辑

Secure context

This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The keys() method in the XRInputSourceArray interface returns a JavaScript iterator which can then be used to iterate over the keys used to reference each item in the array of input sources.

Syntax

xrInputSourceArray.keys();

Parameters

None.

Return value

A JavaScript iterator that can be used to walk through the keys for each entry in the list of input sources. The values returned by the iterator are the indexes of each entry in the list; that is, the numbers 0, 1, 2, and so forth through the index of the last item in the list.

Examples

This example snippet gets the list of inputs for a session and tries to handle each type of input device it supports using.

for (const inputIdx of xrSession.inputSources.keys()) {
  /* the keys are the indexes into the list of inputs */
  checkInput(xrSession.inputSources[inputIdx]);
}

Here, for...of is used to iterate over each of the keys. For each key, the input is retrieved using the index with array notation: xrSession.inputSources[inputIdx].

Specifications

[1] See Iterator-like methods in Information contained in a WebIDL file for information on how an iterable declaration in an interface definition causes entries(), forEach(), keys(), and values() methods to be exposed from objects that implement the interface.

Browser compatibility

BCD tables only load in the browser

See also

• Inputs and input sources
• The XRInputSourceArray method values()
• The Array method keys()
• XRInputSource