javascript 解析csv 的function

function CSVToArray( strData, strDelimiter,rowstoread ){
        // Check to see if the delimiter is defined. If not,
        // then default to comma.
        strDelimiter = (strDelimiter || ",");

        // Create a regular expression to parse the CSV values.
        var objPattern = new RegExp(
                (
                        // Delimiters.
                        "(\\" + strDelimiter + "|\\r?\\n|\\r|^)" +

                        // Quoted fields.
                        "(?:\"([^\"]*(?:\"\"[^\"]*)*)\"|" +

                        // Standard fields.
                        "([^\"\\" + strDelimiter + "\\r\\n]*))"
                ),
                "gi"
                );


        // Create an array to hold our data. Give the array
        // a default empty first row.
        var arrData = [[]];

        // Create an array to hold our individual pattern
        // matching groups.
        var arrMatches = null;


        // Keep looping over the regular expression matches
        // until we can no longer find a match.
        var numread = 0;
        while (arrMatches = objPattern.exec( strData )){
                
                // Get the delimiter that was found.
                var strMatchedDelimiter = arrMatches[ 1 ];

                // Check to see if the given delimiter has a length
                // (is not the start of string) and if it matches
                // field delimiter. If id does not, then we know
                // that this delimiter is a row delimiter.
                if ( strMatchedDelimiter.length && (strMatchedDelimiter != strDelimiter)){
                        numread++;
                        if (rowstoread && rowstoread == numread) break;
                        // Since we have reached a new row of data,
                        // add an empty row to our data array.
                        arrData.push( [] );

                }


                // Now that we have our delimiter out of the way,
                // let's check to see which kind of value we
                // captured (quoted or unquoted).
                if (arrMatches[ 2 ]){

                        // We found a quoted value. When we capture
                        // this value, unescape any double quotes.
                        var strMatchedValue = arrMatches[ 2 ].replace(
                                new RegExp( "\"\"", "g" ),
                                "\""
                                );
                                
                        

                } else {

                        // We found a non-quoted value.
                        var strMatchedValue = arrMatches[ 3 ];

                }
                

            

                // Now that we have our value string, let's add
                // it to the data array.
                arrData[ arrData.length - 1 ].push( strMatchedValue );
                
                
        }

        // Return the parsed data.
        return( arrData );
}