question about Javascript?

Question

I created a function and I want to behavior with that function's element like javascript code.
you will understand my meaning with the following example:

function a(elem){
}

a("2+2") answer=4
a("5^2") answer=25
a("4+2+9") answer=15
a("6*5+4") answer=34

Can you help me?

Answer 1

You're passing in a string expression to be evaluated, so you could just use the eval() function by itself or return eval(elem) which will return the evaluation from your function.

function a(elem) {
return eval(elem);
}

x = a("2 + 2");
alert(x);

or just:

x = eval("2 + 2");
alert(x);

Answer 2

thanks a lot