javascript global function

window.myGlobalVariable = "I am totally a global Var"; //define a global variable
var myOtherGlobalVariable="I too am global as long as I'm outside a function";

const color = 'blue'

const returnSkyColor = () => {
  return color; // blue 
};

console.log(returnSkyColor()); // blue

var carName = "Volvo";
// code here can use carName

function myFunction() {
  // code here can also use carName 
}

function isValidRequired(input){
  input.value.trim() === '' || input.value.trim() === null;
}
  function checkNameReq(input){  
    if(isValidRequired(input)){
      alert('Error');
    }
    else{
      alert('Success');
    }
  }

window.my_function = function(){
	//
}