JS_GetStringBytes 编辑

Obsolete since JSAPI 1.8.5
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

Convert a JavaScript string to a C string.

Syntax

char *
JS_GetStringBytes(JSString *str);

const char *
JS_GetStringBytesZ(JSContext *cx, JSString *str); // Added in JSAPI 1.8.2

Name	Type	Description
cx	JSContext *	(JS_GetStringBytesZ and JS_EncodeString only) A context.
str	JSString *	String to retrieve bytes from.

Description

JS_GetStringBytes and JS_GetStringBytesZ convert the specified JavaScript string, str, to a C string (an array of 8-bit chars). If JS_CStringsAreUTF8 is true, then the returned string is UTF-8, and the conversion is lossless. Otherwise the high byte is simply dropped from each jschar. On success, the return value is a pointer to the char array, which is null-terminated. On failure, JS_GetStringBytes returns a pointer to a null-terminated empty string; JS_GetStringBytesZ returns NULL.

Note: JS_GetStringBytes() and JS_GetStringBytesZ() have both been removed as of JavaScript 1.8.5 (Firefox 4). Instead, you should use JS_EncodeString, JS_GetStringEncodingLength, JS_EncodeStringToBuffer.

The array returned by JS_GetStringBytes or JS_GetStringBytesZ is automatically freed when str is finalized by the JavaScript garbage collection mechanism. The application must not modify the contents of the array.

Note that for non-ASCII strings, if JS_CStringsAreUTF8 is false, these functions can return a corrupted copy of the contents of the string. Use JS_GetStringChars to access the 16-bit characters of a JavaScript string without conversions or copying.

See Also

• JS_EncodeString
• JS_EncodeStringToUTF8
• JS_GetStringEncodingLength
• JS_EncodeStringToBuffer
• JS_CompareStrings
• JS_GetStringLength
• JS_ValueToString
• bug 607292