console.log(2 + '2') // 22
    console.log(2 - '2') // 0

    /*
        + is a number or string operator. If both operands are number, it adds. Otherwise it concatenates.
        - is a number operator.
    */
        

    console.log(5 < 6 <7) // true
    console.log(7 > 6 >5) // false

    /*
        5 < 6 < 7 ==(5<6=true)==> true < 7 ==(1<7)==> true
        7 > 6 > 5 ==(7>6=true)==> true > 5 ==(1>5)==> false
    */
        

    let a = function() { return arguments; }
    let b = () => { return arguments; }

    console.log(a("hi")) // "hi"
    console.log(b("hi")) //

    /* "arguments" doesn't bind with arrow function. Alternatively we can use triple-dot parameters in arrow function. */
        

    let p1 = {"name": "abc"};
    Object.freeze(p1);
    p1.age = 10;
    console.log(p1); // { name: 'abc' }
    p1.name = "bcd";
    console.log(p1); // { name: 'abc' }

    let p2 = {"name": "abc"};
    Object.seal(p2);
    p2.age = 10;
    console.log(p2); // { name: 'abc' }
    p2.name = "bcd";
    console.log(p2); // { name: 'bcd' }

    /*
        Object.freeze(person) restricts from updating an object
        Object.freeze(person) restricts from adding a new property to an object
    */
        

    console.log(Math.max()) // -Infinity

    /* lowest value so that it can get the max value after comparison */
        

    console.log([] + []) // empty string

    /*
        + applies to either number or string. If neither, it typecases to string.
        String([]) = String({}) = empty string
    */
        

    function a() {
      return 'hello'
    }

    const b = a 'hi'
    console.log(b); // hello

     /* a 'hi' = a('hi') */
        

    function y() {
      console.log(this.length)
    }

    var x = {
      length: 5,
      method: function(y) {
        arguments[0]();
      }
    };

    x.method(y, 1); // 2

    /*
        x's method gets 2 arguments: { [Function: y], 1 }
        so, this for function y is { [Function: y], 1 }
        Hence this.length = 2
    */
        

    var x = "constructor"
    console.log(x[x](01)) // "01"

    /*
        x is a string
        x[x] = x["constructor"] = x.constructor
        constructor of any string is a String function
        passing any value to String function gets the value in String
    */
        

    console.log(0.1 + 0.2); // 0.30000000000000004

    /*
        as decimals are in base 10, but computer only understands base 2; this bug is encountered
    */
        

    const a = [1, 2, 3, 4, 5]
    console.log(...arr)         // 1 2 3 4 5
        

    function getAge(...args) {
      console.log(typeof args);    # object
    }

    getAge(21);
        

    const user = {
      email: "default_email@mail.com",
      updateEmail: email => {
          this.email = email;
      }
    }

    user.updateEmail("updated_email@mail.com");
    console.log(user.email);                        // default_email@mail.com
        

    let num = 1;
    console.log(typeof typeof num);              // string