Basic javascript output based question

 1 What will this code output?

console.log(typeof null);      //object

 2 What will this code output?

 console.log(0.1 + 0.2 === 0.3);  // false

 3 What will this code output?

 let a = [1, 2, 3];
 let b = a;
 b[0] = 4;
 console.log(a);
 // Expected Output: `[4, 2, 3]`

 4 What will this code output?

   function test() {
       console.log(a);
       var a = 1;
   }
   test();
// Expected Output:  undefined

5 What will this code output?

 console.log([1] == true);
 // Expected Output: true

6 What will this code output?

 console.log(typeof NaN);
 // Expected Output: number

7 What will this code output?

console.log([2] == [2]);
// Expected Output: false

8 What will this code output?

 console.log(1 + "2" + "2");
// Expected Output: "122"

9 What will this code output?

 let x = 10;
   (function() {
       console.log(x);
       let x = 20;
   })();
// Expected Output: ReferenceError

10 What will this code output?

    var obj = { a: 1 };
    var obj2 = obj;
    obj2.a = 2;
    console.log(obj.a);
 //  Expected Output: 2

11 What will this code output?

 const obj = {
        a: 1,
        b: 2,
        get sum() {
            return this.a + this.b;
        }
    };
    console.log(obj.sum);
  // Expected Output: 3

12 What will this code output?

 const arr = [1, 2, 3];
    arr[10] = 11;
    console.log(arr.length);
   //  Expected Output: 11

13 What will this code output?

console.log(!!"");
// Expected Output: false

14 What will this code output?

  console.log(null == undefined);
// Expected Output: true

15 What will this code output?

    const fn = () => {
        return
        {
            name: "John"
        };
    }
   console.log(fn());
  // Expected Output: undefined