IntersectionObserver.thresholds

草案
本页尚未完工.

这是一个实验中的功能
此功能某些浏览器尚在开发中,请参考浏览器兼容性表格以得到在不同浏览器中适合使用的前缀。由于该功能对应的标准文档可能被重新修订,所以在未来版本的浏览器中该功能的语法和行为可能随之改变。

The IntersectionObserver interface's read-only thresholds property returns the list of intersection thresholds that was specified when the observer was instantiated with IntersectionObserver(). If only one threshold ratio was provided when instanitating the object, this will be an array containing that single value.

See Thresholds in Intersection Observer API to learn how thresholds work.

Syntax

var thresholds = IntersectionObserver.thresholds;

Value

An array of intersection thresholds, originally specified using the threshold property when instantiating the observer. If only one observer was specified, without being in an array, this value is a one-entry array containing that threshold. Regardless of the order your original threshold array was in, this one is always sorted in numerically increasing order.

If no threshold option was included when IntersectionObserver() was used to instantiate the observer, the value of thresholds is simply [0].

Be careful! Although the options object you can specify when creating an IntersectionObserver has a field named threshold, this property is called thresholds. Confusing? Yes. If you accidentally use thresholds as the name of the field in your options, the thresholds array will wind up being simply [0.0], which is likely not what you expect. Debugging chaos may ensue.

Examples

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Specifications

Specification Status Comment
Intersection Observer
IntersectionObserver.thresholds
Working Draft Initial definition

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
thresholds
Experimental
Chrome Full support 51Edge Full support 15Firefox Full support 55
Full support 55
No support 53 — 55
Disabled
Disabled From version 53 until version 55 (exclusive): this feature is behind the dom.IntersectionObserver.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support YesSafari Full support 12.1WebView Android Full support 51Chrome Android Full support 51Firefox Android ? Opera Android ? Safari iOS Full support 12.2Samsung Internet Android Full support 5.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
User must explicitly enable this feature.
User must explicitly enable this feature.