Here is my function
function two(){ console.log('two') } function one(callback){ setTimeout(()=>{ console.log('one') },2000) callback() } one(two) Actual output:
two one My expected Output:
one two My question is how to make changes to these functions so that function two() will be executed after function one()
You could simply call the callback() in your setTimeout's anonymous function like so:
function two() { console.log('two') } function one(callback) { setTimeout(() => { console.log('one'); callback(); // execute callback after everything in setTimeout is executed }, 2000); } one(two);... or, instead, you can use a Promise with ES7's async/await (or using a .then() callback) capabilities like so:
function two() { console.log('two') } async function one(callback) { // make async so we can use `await` await new Promise((resolve, rej) => { // wait for the promise to resolve ... setTimeout(() => { console.log('one'); resolve(); }, 2000) }); callback(); // ... then execute the callback } one(two);This works
let one = new Promise((resolve, reject) =>{ setTimeout(()=>{ console.log('one') resolve(true) },2000) }) one.then((value) => { console.log('two') }) I think callback will be called before other execution.This also works.
function two(){ console.log('two') } function one(one, callback){ console.log(one); callback() } one('one', two); 