User Guide

362 Chapter 21: C-Level Extensibility
JSBool JS_GetElement()
Description
This function reads a single element of an array object.
Arguments
JSContext *cx
, JSObject *obj, unsigned int index, jsval *v
• The cx argument is the opaque JSContext pointer that passes to the JavaScript function.
• The obj argument is a pointer to an array object.
• The index argument is an integer index into the array. The first element is index 0, and the
last element is index (
length - 1).
• The v argument is a pointer to a jsval where the contents of the jsval structure in the array
should be copied.
Returns
A Boolean value: JS_TRUE indicates success; JS_FALSE indicates failure.
JSBool JS_SetElement()
Description
This function writes a single element of an array object.
Arguments
JSContext *cx, JSObject *obj, unsigned int index, jsval *v
• The cx argument is the opaque JSContext pointer that passes to the JavaScript function.
• The obj argument is a pointer to an array object.
• The index argument is an integer index into the array. The first element is index 0, and the
last element is index (
length - 1).
• The v argument is a pointer to a jsval structure whose contents should be copied to the
jsval in the array.
Returns
A Boolean value: JS_TRUE indicates success; JS_FALSE indicates failure.