const a = 1;
          const add = (a, b) => a + b;
          const a = () => {
            console.log(123)
          }
          var const let for while
          function() linear-gradient()
          .myDiv{ background-color: pink; }
          console.log("hello", true)
          /* comment */
          & | $ + − = ~ [] () {} / ; : " @ % 
          0 1 2 3 4 5 6 7 8 9
          {
            "name": "John",
            "age": 30,
            "city": "New York"
          }