callback.js

// call back 
// task Go to the school (late) , study well (second) , come to a good position  (first) - sync method 
//  task ; give only name after 10 sec()
// // sync means that things happpen one after another in order 

function walk (callback){
    setTimeout(() => {
        console.log("walk the dog");
        callback()
    },2000);
}
function clean (callback){
    setTimeout(()=> {
        console.log("clean the car");
    },500);
}
walk(clean);

// call back hell 

function walk (callback){
    setTimeout(() => {
        console.log("walk the dog");
        callback()
    },2000);
}
function clean (callback){
    setTimeout(()=> {
        console.log("clean the car");
        callback()
    },500);
}

function trash (callback){
    setTimeout(() => {
        console.log("put the tarsh out");
    },100)
        
}
walk (()=>{
    clean(()=>{
        trash(()=>{})
    })
})

//task Go to the school (late) , study well (second) , come to a good position  (first) - sync method 

function school (callback){
    setTimeout(()=>{
        console.log("Go to school on time");
        callback()
    },2000)
}
function study(callback){
    setTimeout(() => {
        console.log("Study well all subjects");
        callback()
        }, 500)
}
function position(callback){
    setTimeout(()=>{
        console.log("Come to good postion A grade");
        },100)
}
school(()=>{
    study(()=>{
        position(()=>{
    })
})
})