JavaScript error handling: can I throw an error inside a ternary operator?

Question

Am I allowed to throw an error inside a ternary operator? Is this valid:

function foo(params) {

    var msg = (params.msg) ? params.msg : (throw "error");

    // do stuff if everything inside `params` is defined
}

What I'm trying to do is make sure all of the parameters needed, which are in a param object, are defined and throw an error if any one is not defined.

If this is just foolish, is there a better approach to doing this?

question from:https://stackoverflow.com/questions/9370606/javascript-error-handling-can-i-throw-an-error-inside-a-ternary-operator

Answer 1

You could do this:

function foo(params) {

    var msg = (params.msg) ? params.msg : (function(){throw "error"}());

    // do stuff if everything inside `params` is defined
}

I wouldn't really recommend it though, it makes for unreadable code.

This would also work (not that it's really much better):

function foo(params) {

    var msg = params.msg || (function(){throw "error"}());

    // do stuff if everything inside `params` is defined
}

---

Or for a cleaner approach, make a named function.

function _throw(m) { throw m; }

function foo(params) {

    var msg = params.msg || _throw("error");

    // do stuff if everything inside `params` is defined
}