How can i asign value to variables stored in an array of string?

Question

hi
how can i asign value to variables stored in an array of string. i need to do it so that i can evaluate a math expression by usin those values. for example, i have a string array like [x, y, z, k]. now i need to asign 2.0 to x, 3.0 to y and so on. then if i type x+y, the program should evaluate the expression by usin x=2.0 and y=3.0. i am usin JEP for parsing and evaluating.
any help or suggestion would be much apreciated.
here is how i got the array
System.out.println("Type first expression");
BufferedReader br1 = new BufferedReader( new
                     InputStreamReader(System.in));
String expression1 = br1.readLine();
Jep jep = new Jep();
Node node1 = jep.parse(expression1);
TreeAnalyzer Ta1 = new TreeAnalyzer(node1);
Map<Variable, Integer> map1 = Ta1.getVariables();
/**The following will convert the variable names to a sorted array*/
     /**with the result in varNames.*/
String[] res1 = new String[map1.size()];
            int i=0;
            for(Variable v:map1.keySet())
                res1[i++]=v.getName();  
System.out.println(Arrays.toString(res1));

Answer 1

I could not use HashMap as those variables are to be retrieved from any expression typed by user and thus unknown to me beforehand.
System.out.println("Type first expression");
BufferedReader br1 = new BufferedReader( new
                     InputStreamReader(System.in));
String expression1 = br1.readLine();
Jep jep = new Jep();
Node node1 = jep.parse(expression1);
TreeAnalyzer Ta1 = new TreeAnalyzer(node1);
Map<Variable, Integer> map1 = Ta1.getVariables();then i have converted them to a sorted array
String[] res1 = new String[map1.size()];
                 int i=0;
                 for(Variable v:map1.keySet())
                     res1[i++]=v.getName();              
                 System.out.println(Arrays.toString(res1));now i need to assign random double values to those variables.
and then use those double values for variables when evaluating the expression.
pls help.