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JS_HasOwnProperty 编辑

This article covers features introduced in SpiderMonkey 45

Determine whether a JavaScript object has a specified own property.

Syntax

bool
JS_HasOwnProperty(JSContext* cx, HandleObject obj, const char* name,
                  bool* foundp)

bool
JS_HasOwnPropertyById(JSContext* cx, HandleObject obj, HandleId id,
                      bool* foundp)

Name	Type	Description
`cx`	`JSContext *`	A context. Requires request. In a `JS_THREADSAFE` build, the caller must be in a request on this `JSContext`.
`obj`	`JS::HandleObject`	Object to search on for the property.
`name` or `id`	`const char *` or `JS::HandleId`	Name of the property to look up.
`foundp`	`bool *`	Non-null pointer to a variable of type `bool`. On success, `JS_HasOwnProperty` stores `true` in this variable if `obj` has an own property with the given `name`, and `false` if not.

JS_HasOwnProperty searches an object, obj, for an own property with the specified name. It behaves like the JavaScript expression Object.hasOwnProperty(obj, name). JS_HasOwnPropertyById is the same but takes a JS::HandleId for the property name.

If the property exists, this function sets *foundp to true and returns true.

If the object obj has no such property, the function sets *foundp to false and returns true (to indicate that no error occurred).

If an error occurs during the search, the function returns false, and the value of *foundp is undefined.

JS_HasOwnProperty 编辑

Syntax

Description

See Also

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友情链接

JS_HasOwnProperty 编辑

Syntax

Description

See Also

如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

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友情链接

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。