asynchronus.js

/*function doSomething(callback) { 
    callback();
   }
   function sayHi() {
    console.log("Hi!");
   }
   doSomething(sayHi);  //passing another function in a function as a refrence using callback called out other function
*/


//callback example 02

function hey(ret){
    ret="yes"
  console.log("return works! through callback "+ret);
}
function there(a,b,callback){
    let ret;
    addup=a+b;
    console.log("main function calling : "+addup);
    callback(ret);
}
there(3,4,hey); // passing another function in a function as a refrence using callback called out other function

/*
function judge(grade) {
    switch (true) {
    case grade == "A":
    console.log("You got an", grade, ": amazing!");
    break;
    case grade == "B":
    console.log("You got a", grade, ": well done!");
    break;
    case grade == "C":
    console.log("You got a", grade, ": alright.");
    break;
    case grade == "D":
    console.log("You got a", grade, ": hmmm...");
    break;
    default:
    console.log("An", grade, "! What?!");
    }
   }
   function getGrade(score, callback) {
    let grade;
    switch (true) {
    case score >= 90:
    grade = "A";
    break;
    case score >= 80:
    console.log(score);
    grade = "B";
    break;
    case score >= 70:
    grade = "C";
    break;
    case score >= 60:
    grade = "D";
    break;
    default:
    grade = "F";
    }
    callback(grade);
   }
   getGrade(85, judge);
   */