JS_HasProperty
Table of contents
- 1. Syntax
- 2. Description
- 3. See Also
Determine whether a JavaScript object has a specified property.
Syntax
JSBool JS_HasProperty(JSContext *cx, JSObject *obj, const char *name, JSBool *foundp); JSBool JS_HasUCProperty(JSContext *cx, JSObject *obj, const jschar *name, size_t namelen, JSBool *foundp);
| Name | Type | Description |
|---|---|---|
cx |
JSContext * |
Pointer to a JS context from which to derive runtime information.
Requires request. (In a JS_THREADSAFE build, the caller must be in a request on this JSContext.)
|
obj |
JSObject * |
Object to search on for the property. |
name |
const char * or const jschar * |
Name of the property to look up. |
namelen |
size_t |
(only in JS_HasUCProperty) The length of name in characters, or -1 to indicate that name is null-terminated. |
foundp |
JSBool * |
Non-null pointer to a variable of type JSBool. On success, JS_HasProperty stores JS_TRUE in this variable if obj has a property with the given name, and JS_FALSE if not. |
Description
JS_HasProperty examines a specified JS object, obj, its scope and prototype links, for a property with the specified name. JS_HasUCProperty is the corresponding Unicode API.
If the property exists, this function sets *foundp to JS_TRUE and returns JS_TRUE.
If the object obj has no such property, the function sets *foundp to JS_FALSE and returns JS_TRUE (to indicate that no error occurred).
If an error occurs during the search, the function returns JS_FALSE, and the value of *foundp is undefined.
Page last modified 20:11, 21 Aug 2008 by Jorend