Question

I have an array with the following value:

2, *, 5

How can I execute this string like so:

2 * 5

so the result returned is 10?

Answer 1

The most horribly insecure way possible would be to do something like this:

eval([2,"*",5].join(''))

But I could never recommend doing that, like ever. The “right” way to do it would be to write some kind of parser.

var ops = [2,"*",5]

var val = ops.shift();
while(ops.length > 0) {
    var item = ops.shift();
    switch(item) {
        case "*": val *= ops.shift();
        case "+": val += ops.shift();
        case "-": val -= ops.shift();
        case "/": val /= ops.shift();
    }
}

This would essentially work like a very simple calculator… but I still couldn’t really recommend this approach.

What are you trying to do exactly? Maybe there is a better way to model what you are trying to do other than an array?