Promise ajax

It’s easy, haha, accumulate a little every day

Start by implementing a simple promise

<script> var fun = new Promise((resolve, reject) => { setTimeout(() => { console.log(111); }, 1000) console.log(' I created a new promise'); }) fun.then((x) => { console.log(x); }) </script>Copy the code

Promise to implement ajax

 <script>
        var myAjax = (url) => {
            return new Promise((resolve, reject) => {
                var xhr = new XMLHttpRequest()
                xhr.open('get', url)
                xhr.send(data)
                xhr.onreadystatechange = () => {
                    if (xhr.status == 200 && readyState == 4) {
                        var json = JSON.parse(xhr.responseText)
                        resolve(json)
                    } else {
                        reject('error')
                    }
                }
            })
        }
    </script>
    
    
    
Copy the code

Incidentally ask have big guy to be able to push inside!!