Obsolete since JSAPI 35
This feature is obsolete.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.
jschar is the type of JavaScript "characters", the 16-bit elements that make up strings.
jschar, a typedef for the standard C++ type char16_t, will be removed in JSAPI 38. Functions that use jschar will use char16_t directly. Embedder code should use char16_t, too. (See bug 1063962.)
As required by the ECMAScript standard, ECMA 262-3 §4.3.16, JavaScript strings are arbitrary sequences of 16-bit values. A string may contain unmatched surrogates, which are not valid UTF-16. It may also contain zeroes ('\0').
To get the characters of a JavaScript string, use JS_GetStringChars.