用JS如何把utf8转换成Unicode

function Utf8ToUnicode(strUtf8) {var bstr = "";var nTotalChars = strUtf8.length; // total chars to be processed.var nOffset = 0; // processing point on strUtf8var nRemainingBytes = nTotalChars; // how many bytes left to be convertedvar nOutputPosition = 0;iCode, iCode1, iCode2; // the value of the unicode.while (nOffset < nTotalChars) {iCode = strUtf8.charCodeAt(nOffset);if ((iCode & 0x80) == 0) // 1 byte.{if (nRemainingBytes < 1) // not enough databreak;bstr += String.fromCharCode(iCode & 0x7F);nOffset++;nRemainingBytes -= 1;}else if ((iCode & 0xE0) == 0xC0) // 2 bytes{iCode1 = strUtf8.charCodeAt(nOffset + 1);if (nRemainingBytes < 2 || // not enough data(iCode1 & 0xC0) != 0x80) // invalid pattern{break;}bstr += String.fromCharCode(((iCode & 0x3F) << 6) | (iCode1 & 0x3F));nOffset += 2;nRemainingBytes -= 2;} else if ((iCode & 0xF0) == 0xE0) // 3 bytes{iCode1 = strUtf8.charCodeAt(nOffset + 1);iCode2 = strUtf8.charCodeAt(nOffset + 2);if (nRemainingBytes < 3 || // not enough data(iCode1 & 0xC0) != 0x80 || // invalid pattern(iCode2 & 0xC0) != 0x80) {break;}bstr += String.fromCharCode(((iCode & 0x0F) << 12)| ((iCode1 & 0x3F) << 6) | (iCode2 & 0x3F));nOffset += 3;nRemainingBytes -= 3;} else// 4 or more bytes -- unsupportedbreak;}if (nRemainingBytes != 0) { // bad UTF8 string. return "";}return bstr;}