buffer.write(string, [offset], [length], [encoding])

buf = new Buffer(256);   len = buf.write('\u00bd + \u00bc = \u00be', 0);   console.log(len + " bytes: " + buf.toString('utf8', 0, len));

Buffer.prototype.write = function(string, offset, length, encoding) {   // allow write(string, encoding)   if (util.isString(offset) && util.isUndefined(length)) {     encoding = offset;     offset = 0;   // allow write(string, offset[, length], encoding)   } else if (isFinite(offset)) {     offset = ~~offset;     if (isFinite(length)) {       length = ~~length;     } else {       encoding = length;       length = undefined;     }   // XXX legacy write(string, encoding, offset, length) - remove in v0.13   } else {     if (!writeWarned) {       if (process.throwDeprecation)         throw new Error(writeMsg);       else if (process.traceDeprecation)         console.trace(writeMsg);       else         console.error(writeMsg);       writeWarned = true;     }     var swap = encoding;     encoding = offset;     offset = ~~length;     length = swap;   }   var remaining = this.length - offset;   if (util.isUndefined(length) || length > remaining)     length = remaining;   encoding = !!encoding ? (encoding + '').toLowerCase() : 'utf8';   if (string.length > 0 && (length < 0 || offset < 0))     throw new RangeError('attempt to write beyond buffer bounds');   var ret;   switch (encoding) {     case 'hex':       ret = this.hexWrite(string, offset, length);       break;     case 'utf8':     case 'utf-8':       ret = this.utf8Write(string, offset, length);       break;     case 'ascii':       ret = this.asciiWrite(string, offset, length);       break;     case 'binary':       ret = this.binaryWrite(string, offset, length);       break;     case 'base64':       // Warning: maxLength not taken into account in base64Write       ret = this.base64Write(string, offset, length);       break;     case 'ucs2':     case 'ucs-2':     case 'utf16le':     case 'utf-16le':       ret = this.ucs2Write(string, offset, length);       break;     default:       throw new TypeError('Unknown encoding: ' + encoding);   }   return ret; };