Executing a string without eval or is eval ok to use here?

Is there a better way of executing the string "getData" without eval or eval a good option in this case since what is being evaluated is not user generated?

object.myMainObject(Marcus)

object = {
    Data = {
        Marcus : function(){
            alert('marcus function')
        },
        James : function(){
            alert('james function')
        }
    }

    myMainObject : function(string){
        getData = "object.Data." + string + "()"

        eval(getData)
    }
}

Solution

eval is completely unnecessary for this case, just use the bracket notation to access the dynamically named property:

var object = {
    Data : {
        Marcus : function(){
            alert('marcus function');
        },
        James : function(){
            alert('james function');
        }
    }

    myMainObject : function(string){
        var getData = object.Data[string]();
    }
};

object.myMainObject("Marcus"); // 'marcus function'

Notes:

There were some syntax errors in the way you were defining object (you were using =, instead of : ).
You weren't using the var statement to declare object nor getData, please, when declaring variables, use the var statement, otherwise, they will end up as properties of the global object.
As a safety measure, you could check if the member that's being accessed is actually a function before calling it, e.g.:
```
//...
var getData;
if (typeof object.Data[string] == 'function') {
   getData = object.Data[string]();
}
//...
```