callback function js

JavaScript
/*
A callback function is a function passed into another function
as an argument, which is then invoked inside the outer function
to complete some kind of routine or action. 
*/
function greeting(name) {
  alert('Hello ' + name);
}

function processUserInput(callback) {
  var name = prompt('Please enter your name.');
  callback(name);
}

processUserInput(greeting);
// The above example is a synchronous callback, as it is executed immediately.function greeting(name) {
  alert('Hello ' + name);
}

function processUserInput(callback) {
  var name = prompt('Please enter your name.');
  callback(name);
}

processUserInput(greeting);const add = (num1, num2) => num1 + num2;

const result = (num1, num2, cb) => {
  return "result is:" + cb(num1, num2);
}

const res = result(12, 13, add);const ironMan = withGloves(withBoots(withArmor(withHelmet(TonyStark))));
Source

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