js+ajax 上传多图片，并删除

<div class="df mb20">
       <input type="text" readonly placeholder="请选择图片" class="form-control col-sm-6"> 
       <input type="text" style=" 100px;" readonly value="请选择图片" class="btn btn-default" >
       <input type="file" id="picture" name="cover" multiple class="btn btn-default" style=" 100px;height:35px;line-height:85px;position: absolute;right: 15px;z-index: 1;background: transparent;" />
       <input type="hidden" name="s_imgpath[]" id="s_imgpath" >
</div>
<div id="previewImg" style="display: flex;justify-content: flex-start;align-items: flex-start;"></div>
<style>
       #previewImg div{margin-right: 10px;margin-bottom: 10px;}
       .hide{display: none !important;}
       #previewImg div{position: relative;}
       .show{width: 20px;height: 20px;background: #0275D8;border-radius: 50%;position:absolute;top: 0;right: 0;z-index: 99}
       .show::after{content: 'x';color: #fff;width:20px;text-align: center;position: absolute;top:0;left: 0;right: 0;bottom: 0;margin:0 auto;}
</style>

// 多张图片
    var arr=[]
    $('#picture').on('change', function(){
        var imgFiles = $(this)[0].files
        console.log("多张图片",imgFiles)
        var formData =  new FormData();
        for (i=0;i<imgFiles.length;i++){
            filePath = imgFiles[i].name;
            fileFormat = filePath.split('.')[1].toLowerCase()  
            if( !fileFormat.match(/png|jpg|jpeg/) ) {  
                alert('上传错误,文件格式必须为：png/jpg/jpeg')
                return   
            }
            formData.append('upfile', $(this)[0].files[i]); //添加图片信息的参数
            var preview = document.getElementById("previewImg")
            var div = document.createElement('div')
            var a = document.createElement('a')
            var img = document.createElement('img')
            $.ajax({
                url: "/upload",
                type: "post",
                dataType: "json",
                cache: false,
                mimeType: "multipart/form-data",
                data: formData,
                processData: false,// 不处理数据
                contentType: false, // 不设置内容类型
                async:false,
                success:function (result){
                    arr[i]=result
                    img.width = 150
                    img.src = arr[i]
                    preview.appendChild(div)
                    div.appendChild(a)
                    div.appendChild(img)
                    $('#s_imgpath').val(arr)
                    //这儿  把我返回的值， 插入到那个数组里面 s_imgpath[]
                }
            });
        }
    })
    //控制"按钮"显示与隐藏
    $("#previewImg").off("mouseenter","div").on("mouseenter","div",function(){
        var that=this;
        var dom=$(that).children("a");
        dom.removeClass("hide");
        dom.addClass("show");
        //为点击事件解绑，防止重复执行
        dom.off("click");
        dom.on("click",function(){
            //删除当前图片
            dom.parent().remove();
            var imgsrc = dom.parent().children("img")[0].src   //当前图片src
            arr.removeByValue(imgsrc);             //从数组中移除当前图片
            $('#s_imgpath').val(arr)               //给input重新赋值
        });
    }).off("mouseleave","div").on("mouseleave","div",function(){
        var that=this;
        $(that).children("a").addClass("hide");
    })
    Array.prototype.removeByValue = function(val) {    //删除数组中元素
      for(var i=0; i<this.length; i++) {
        if(this[i] == val) {
          this.splice(i, 1);
          break;
        }
      }
    }