User Guide

546 C-Level Extensibility
JSBool JS_ValueToBoolean()
Usage
JSBool JS_ValueToBoolean(JSContext *cx, jsval v, JSBool *bp);
Description
Method; extracts a function argument from a jsval structure, converts it to a Boolean value
(if possible), and passes the converted value back to the caller.
Arguments
JSContext *cx, jsval v, JSBool *bp
■ The cx argument is the opaque JSContext pointer that passes to the JavaScript function.
■ The v argument is the jsval structure from which the Boolean value is to be extracted.
■ The bp argument is a pointer to a JSBool Boolean value. This function stores the
converted value in
*bp.
Returns
A Boolean value: JS_TRUE indicates success; JS_FALSE indicates failure.
JSBool JS_ValueToObject()
Usage
JSBool JS_ValueToObject(JSContext *cx, jsval v, JSObject **op);
Description
Method; extracts a function argument from a jsval structure, converts it to an object (if
possible), and passes the converted value back to the caller. If the object is an array, use
JS_GetArrayLength() and JS_GetElement() to read its contents.
Arguments
JSContext *cx, jsval v, JSObject **op
■ The cx argument is the opaque JSContext pointer that passes to the JavaScript function.
■ The v argument is the jsval structure from which the object is to be extracted.
■ The op argument is a pointer to a JSObject pointer. This function stores the converted
value in
*op.
Returns
A Boolean value: JS_TRUE indicates success; JS_FALSE indicates failure.