Given a string describing a Javascript function, convert it to a Javascript function

Question

Say I\'ve got a Javascript string like the following

var fnStr = \"function(){blah1;blah2;blah3; }\" ;

(This may be from an expression the

Answer 1

The Function constructor creates a new Function object. In JavaScript every function is actually a Function object.

// Create a function that takes two arguments and returns the sum of those arguments
var fun = new Function("a", "b", "return a + b");
// Call the function
fun(2, 6);
Output: 8

Answer 2

one way:

     var a = 'function f(){ alert(111); } function d(){ alert(222);}';  
     eval(a);
     d();

second more secure way to convert string to a funciton:

     // function name and parameters to pass
    var fnstring = "runMe";
    var fnparams = ["aaa", "bbbb", "ccc"];

    // find object
    var fn = window[fnstring];

    // is object a function?
    if (typeof fn === "function") fn.apply(null, fnparams);


    function runMe(a,b){
      alert(b);
    }

look working code http://plnkr.co/edit/OiQAVd9DMV2PfK0NG9vk