Hoisting Issue

hoisting.js

function printName(isFirstName){
  console.log(firstName); // Variables hoisted to the top
  console.log(lastName);
  
  if (isFirstName){
    var firstName = 'Prasanna';
  }else {
    var lastName = 'V'
  }
}
printName(true);
/* Output :

undefined
undefined 

*/

//------- Safe hoisting -----

function printNameSafely(isFirstName){
  console.log(firstName); // Variables are not hoisted to the top
  console.log(lastName);
  
  if (isFirstName){
    console.log(firstName); // Still variables are hoisted within the block
    let firstName = 'Prasanna';
  }else {
    let lastName = 'V'
  }
}

printNameSafely(true);
/* Output :
"ReferenceError: firstName is not defined
*/