How can I convert a string into a math operator in javascript [duplicate]

Question

If I've got a string that is a mathematic equation and I want to split it and then calculate it. I know I can use the eval() function to do this, but I'm interested if there's an alternative way to do this - specifically by splitting the strings first. So I've got something like

var myString = "225 + 15 - 10" var newString = myString.split(" "); 

This would turn myString into an array:

["225", "+", "15", "-", "10"]; 

My next task is to turn all the odd-numbered strings into integers, which I think I could use parseInt(); for. My question is, how do I turn the "+" and "-" into actual arithmetic operators? So that at the end I am left with a mathematic expression which I can calculate?

Is this possible?

Answer 1

var math_it_up = {     '+': function (x, y) { return x + y },     '-': function (x, y) { return x - y } }​​​​​​​;  math_it_up['+'](1, 2) == 3;