How to convert mixed ascii and unicode to a string in javascript?

I have a mixed source of unicode and ascii characters, for example:

var source = "\u5c07\u63a2\u8a0e HTML5 \u53ca\u5176\u4ed6";

How do I convert it to a string by leveraging and extending the below uniCodeToString function written by myself in Javascript? This function can convert pure unicode to string.

function uniCodeToString(source){
    //for example, source = "\u5c07\u63a2\u8a0e"
    var escapedSource = escape(source);
    var codeArray = escapedSource.split("%u");
    var str = "";
    for(var i=1; i<codeArray.length; i++){
     开发者_JAVA技巧   str += String.fromCharCode("0x"+codeArray[i]);
    }
    return str;
}

Use encodeURIComponent, escape was never meant for unicode.

   var source = "\u5c07\u63a2\u8a0e HTML5 \u53ca\u5176\u4ed6";


    var enc=encodeURIComponent(source)

   //returned value: (String)
    %E5%B0%87%E6%8E%A2%E8%A8%8E%20HTML5%20%E5%8F%8A%E5%85%B6%E4%BB%96

    decodeURIComponent(enc)

    //returned value: (String)
    將探討 HTML5 及其他

I think you are misunderstanding the purpose of Unicode escape sequences.

var source = "\u5c07\u63a2\u8a0e HTML5 \u53ca\u5176\u4ed6";

JavaScript strings are always Unicode (each code unit is a 16 bit UTF-16 encoded value.) The purpose of the escapes is to allow you to describe values that are unsupported by the encoding used to save the source file (e.g. the HTML page or .JS file is encoded as ISO-8859-1) or to overcome things like keyboard limitations. This is no different to using \n to indicate a linefeed code point.

The above string ("將探討 HTML5 及其他") is made up of the values 5c07 63a2 8a0e 0020 0048 0054 004d 004c 0035 0020 53ca 5176 4ed6 whether you write the sequence as a literal or in escape sequences.

See the String Literals section of ECMA-262 for more details.