JSFiddle - React, Tailwind, and code Playground

JavaScript

//An async function returning after half a second
function asyncFunc(text, callback){
    setTimeout(function() {
        callback(text);
     }, 500);    
}

//Demonstrates nesting of async functions
function asyncNested(){
    asyncFunc('1', function(text){
        console.log('async 1');
        asyncFunc('2', function(text){
            console.log('async 2');
            asyncFunc('3', function(text){
                console.log('async 3');
            });
        });
    });
}

asyncNested();