js to upload pictures to the server

//Upload multiple pictures multiple
<input type="file" id="file" multiple>
//Native submit button <input type="submit">

<script>
    // Define an array to receive images converted to base64 let ArrayImg=[]
    var index = 0; //Add a unique identifier to the image for easy deletion // Get the element on the page let input=document.getElementById('file')
    console.log(input);
    // Bind oncheange event input.onchange=function(){
      var file = this.files[0] //Get the file selected on the page [N] refers to the number of files to get // console.log(file);
      var iLen = this.files.length; //Get the image length// console.log(iLen);
      for(var i=0;i<iLen;i++){ //Display multiple images on the page or upload them through a loop //Preview local cache var filereader = new FileReader() //Create a local cache object //Convert the local cache of the acquired file to bese64
      filereader.readAsDataURL(this.files[i]) //Convert to base64 and store in free attribute reader.result console.log([i]);
        filereader.onload = function () { //Get this.result through onload event // console.log(this.result,333);
        ArrayImg.push(this.result)
        // Include the img display image through the html tag and store it in a variable let img1=`<div id="divimg"><img src="${this.result}" alt="" id="id_img"></div>`  
        // Create a new div
        let div = document.createElement('div')
        div['index'] = index; // Add a unique identifier to div for easy removal // Put the uploaded img1 into the newly created div div.innerHTML=img1
        console.log(ArrayImg,'image array');
        //Then insert it into the DOM tree through DOM operation to display the picture document.getElementsByTagName('body')[0].appendChild(div) //Insert into the DOM tree// console.log(img);
        // Delete the currently clicked div and the base64 address in the currently clicked image array by binding the click event to div div.onclick = function(){  
                    this.remove(); // Delete the image element in the page delete ArrayImg[this.index]; // Delete the data corresponding to the ArrayImg array console.log(ArrayImg,'Image array');
                }
                //inddex records how many times the current loop is done to remove the link address index++ in the ArrayImg array
      }
      }
    }
</script>