why warpping your code in resolved prop makes your sync code act like async code?

loop in side of the promise works like sync code for example

console.log('im working')
function proLoop(){
    return new Promise((resolve ,rejects)=>{
        for (let i = 0; i < 1000000000000; i++) {}
        console.log('loop is done')
    })
}

proLoop();

console.log('im working')

So even if we write is like promise it will get more time and freezes our code In other words it will works synchronically.

i find a solution but why it works?

so the solution is just warp your code as like resolved promise

like this

return Promise.resolve().then( ()=>{
    for (let i = 0; i < 1000000000000; i++) {}
    console.log('loop is done')
})

but why and how???