const value_1 = "1" 

const value_2 = "2"

function add(field_1, field_2){

  return field_1 + field_2;
}


add(+value_1, +value_2); 

const floatToInt = 23.9 | 0;

const user = {

  first_name: "Rowan",

  last_name: "Atkinson"
}

window.user=user

const DemoComponent = ()=>{

const [show, setShow] = useState(false)

   return (<div>

     {show? <Message/>: ''}

</div>)
}

const DemoComponent = ()=>{
const [show, setShow] = useState(false)

   return (<div>
     {show && <Message/>}
    </div>)
}

if (variable1 !== null || variable1 !== undefined || variable1 !== '') {
     let variable2 = variable1;
}

const variable2 = variable1  || 'new';

Math.floor(4.9) === 4 // true

~~4.9 === 4 // true

switch (something) {

  case 1:
    doSomething();

  break;
case 2:
    doSomethingElse();
  break;
case 3:
    doSomethingElseAndOver();
  break;
  // And so on...
}

const cases = {
  1: doSomething,

  2: doSomethingElse,

  3: doSomethingElseAndOver
};

if(x == 1 || x == 5 || x == 7)  {
  console.log('X has some value');
}

([1,5,7].indexOf(x) !=- 1) && console.log('X has some value!');

const param1 =1;
const param2 = 2;
const param3 = 3;
const param4 = 4;


function MyFunc =(param1, param2, param3, param4)=>{
  console.log(param1, param2, param3, param4)
}

MyFunc(param1, param2, param3, param4)

const params = {param1: 1, param2: 2, param3: 3, param4: 4}

function MyFunc =({param1, param2, param3, param4})=>{
  console.log(param1, param2, param3, param4)

}

MyFunc(params)

function Myfunc(value){
   if(value){
     console.log("you have a value")
   }else{
      throw new Error("You don't have a value")
   }
}

function Myfunc(value){
   return !value ? throw new Error("You don't have a value") : console.log("you have a value")
}