Check if browser supports MutationObserver

Question

如何写一个if子句来检查是否支持MutationObserver ？

Answer 1

Try using in operator

The in operator returns true if the specified property is in the specified object.

Syntax

prop in objectName

Parameters

prop

A string or symbol representing a property name or array index (non-symbols will be coerced to strings).

objectName

Name of an object.

if ("MutationObserver" in window) {
  // do stuff
}