Swift, get variable name from a string

Question

I have a question. I know that this can be done in Ruby, not sure about Swift, but never did anything similar. What I\'m working on is a program that works similar to this: if t

Answer 1

Check this out. You can do with NSExpression and KVC.

class myclass:NSObject {

    var a = 10;
    var b = 20;

    override init() {
        super.init();
    }


}

var obj = myclass();

// Expression from user
var expr:NSString = "a+b" ;

//Operators..
let opSet = NSMutableCharacterSet()
opSet.addCharactersInString("+-*/");


let components:NSArray = expr.componentsSeparatedByCharactersInSet(opSet)
let uniqueChars:NSSet = NSSet(array: components)

for variable in uniqueChars
{
    expr = expr.stringByReplacingOccurrencesOfString ( variable as String,
    withString  : NSString(format: "%d", obj.valueForKey(variable as String) as Int),
    options     : NSStringCompareOptions.LiteralSearch,
    range       : NSMakeRange(0,expr.length)         );

}


var result: AnyObject = NSExpression(format: expr).expressionValueWithObject(nil, context: nil)

print (result);