What is the difference between a function call and function reference?

Question

I have the following function

function hello() {
 alert(\"hi!\");
}

Take this piece of code:

var elem = document.getElem         


        

Answer 1

Pretty much all statements in JavaScript have a return value. Unless otherwise specified, functions in JavaScript will return undefined when called. So, the only context in which it would make sense to call your function in this assignment statement if it were to return a function:

function hello() {
    return function() {
        alert("hi!");
    }
}

elem.onclick = hello();