Regular expression in a switch case

Question

Hey guys,
I have a string "52x + 60" and i want to extract 52x and 60 using regular expressions and a switch case
Is this the right way of doing it?
var equation:String = "32x + 5"
var numberExract:RegExp = /\d+/
var xExtract:RegExp = /d+/x/
for(var i:Number=0; i<equation.length; i++)
                    switch(equation.charAt(i))
                              case numberExtract.exec(equation):
                              trace("number");
               break;
               case xExtract.exec(equation):
               trace("x");
               break;
Because it's not tracing anything when i try

Answer 1

Here is a quick and dirty approach - can be customized, optimized and more elegant expressions used:
// equation
var string:String = "x^2 + 5x + 5 - x7 + 8 / 4";
// value replacing xs
var value:Number = 60;
// replace xs with value
// if x comes after digit
string = string.replace(/(?<=\d)x/g, String("*" + value));
// if x comes before digit
string = string.replace(/x(?=\d)/g, String(value + "*"));
// all other xs
string = string.replace(/x/g, String(value));
// remove spaces
string = string.replace(/\s/g, "");
// get pairs with first level math
var pattern:RegExp = /(\d+[\*\^\/]\d+)|\D|\d+/g;
var result:Number = stringToMath(string.match(pattern));
trace("result", result);
function stringToMath(match:Array):Number
    // digits surrounding operator
    var pattern:RegExp = /\d+\D\d+/;
    for (var i:int = 0; i < match.length; i++)
        if (match[i].match(pattern))
            match[i] = String(calculate(match[i]));
    trace("loop result", match);
    return calculteSum(match);
* Calculates sums
* @param    array
* @return
function calculteSum(array:Array):Number
    var result:Number = array[0];
    for (var i:int = 1; i < array.length - 1; i++)
        if (array[i] == "+")
            result += array[i + 1];
        else if (array[i] == "-")
            result -= array[i + 1];
    return result;
* First level math
* @param    string
* @return
function calculate(string:String):Number
    var operator:RegExp = /[\+\*\/\^\-]/g;
    var digits:Array = string.match(/\d+/g);
    var num:Number = 0;
    if (digits && string.match(operator) && digits.length > 1)
        switch (string.match(operator)[0])
            case "*":
                num = digits[0] * digits[1];
                break;
            case "/":
                num = digits[0] / digits[1];
                break;
            case "+":
                num = digits[0] + digits[1];
                break;
            case "-":
                num = digits[0] - digits[1];
                break;
            case "^":
                num = Math.pow(digits[0], digits[1]);
                break;
    return num;