calling a callback function javascript code example

Example 1: create callback function javascript

function add(a, b, callback) {
  if (callback && typeof(callback) === "function") {
    callback(a + b);
  }
}

add(5, 3, function(answer) {
  console.log(answer);
});

Example 2: javascript callback function

const message = function() {  
    console.log("This message is shown after 3 seconds");
}
 
setTimeout(message, 3000);