javascript - Why is the image size I get here NaN?

Question

    <form enctype="multipart/form-data" name="form1">
      <input type="file" name="file">
      <input type="button" value="取得图片的大小" onClick="getSize()">
    </form>
    <img name="pic" alt="在这儿显示图片">

function getSize(){
        size = 0;
        imgURL = form1.file.value;
        imgURLsplice = imgURL.split("\").pop();
        imgURLsplicelocal ="../assets/img/" + imgURLsplice;
        img = new Image();
        img.src = imgURLsplicelocal;
        pic.src = imgURLsplicelocal;
        if (size <= 0){
            size = img.fileSize / 1024;
        }
        alert("图片大小为：" + size + "KB");
    }

Answer 1

img.fileSize is a number not a character

Answer 2

You will know after taking a look at the img.fileSize log.

Answer 3

img是个dom类型<img>的东西啊。怎么可能有fileSize这种东西
$("#file")[0].files[0].size才可以有