JS_GetArrayLength 编辑

Retrieve the number of elements in an array object.

Syntax

bool
JS_GetArrayLength(JSContext *cx, JS::Handle<JSObject*> obj,
                  uint32_t *lengthp);

Description

JS_GetArrayLength gets the .length property of obj as though by calling JS_GetProperty and converts it to a 32-bit unsigned integer. If obj is an array (see JS_IsArrayObject), this is guaranteed to succeed, because the .length property of an array is always a number and can't be deleted or redefined.

On success, JS_GetArrayLength stores the length in *lengthp and returns true. On failure, it reports an error and returns false, and the value left in *lengthp is undefined.

See Also

• MXR ID Search for JS_GetArrayLength
• JS_GetElement
• JS_SetArrayLength