functional_quiz.md

#Quiz:

1. What’s the result of:

    console.log(f());
    function f() {
        return 1;
    }
   

   Answers:

   • null
   • undefined
   • 1
   • error

2. How do these differ?

    function foo() {}
    // versus
    var foo = function() {};
   

3. What’s the result of:

    function f() {
        var a = 5;
        return new Function('b', 'return a + b');
    }
    consoe.log( f()(1) );
   

   Answers:

   • 1
   • 6
   • undefined
   • NaN
   • error

4. What’s the result of:

    var f = function(x) {
        console.log(x)
    }
   
    (function() {
        f(1);
    }())
   

   Answers:

   • nothing
   • 1
   • error
   • depends on browser

5. What’s the result of:

    function() {
        if (true) {
            var a = 5;
        }
        console.log(a);
    }
   

   Answers:

   • nothing
   • 5
   • error
   • depends on browser

6. What’s the result of:

    function f(x, y) {
        x = 10;
        console.log(
            arguments[0],
            arguments[1]
        );
    }
   
    f();
   

   Answers:

   • 10, null
   • 10, undefined
   • undefined, undefined
   • 10, NaN

7. What’s the result of:

    function a(x) {
        return x * 2;
    }
    var a;
    console.log(a);
   

   Answers:

   • error
   • 2
   • undefined
   • body of function

8. What’s the result of:

    (function f() {
        function f() { return 1; }
        return f();
        function f() { return 2; }
    })();
   

   Answers:

   • 1
   • 2
   • undefined
   • depends on browser

9. What’s the result of:

    (function() {
        return typeof arguments;
    })();
   

   Answers:

   • 'object'
   • 'array'
   • 'arguments'
   • 'undefined'

10. What’s the result of:

    var f = function g() { return 'test'; };
    console.log( typeof g() );
    

    Answers:

    • string
    • undefined
    • function
    • error

11. What’s the result of:

    (function() {
        var kittySays = 'Meow';
    })();
    console.log(kittySays);
    

    Answers:

    • 'Meow'
    • undefined
    • null
    • error

12. What’s the result of:

    console.log (f());
    var f = function () { return 1; };
    

    Answers:

    • null
    • undefined
    • 1
    • error

13. What’s the result of:

    var x = 1;
    
    (function() {
        console.log(x);
        return x;
        var x = 2;
    })();
    

    Answers:

    • 2
    • undefined
    • 1
    • error