关于javascript:文件大小换算-js

export function change_size(filesize){    var size = "";    if(filesize < 0.1 * 1024){                         //小于0.1KB，则转化成B        size = filesize.toFixed(2) + "B"    }else if(filesize < 0.1 * 1024 * 1024){            //小于0.1MB，则转化成KB        size = (filesize/1024).toFixed(2) + "KB"    }else if(filesize < 0.1 * 1024 * 1024 * 1024){     //小于0.1GB，则转化成MB        size = (filesize/(1024 * 1024)).toFixed(2) + "MB"    }else{                                            //其余转化成GB        size = (filesize/(1024 * 1024 * 1024)).toFixed(2) + "GB"    }    var sizeStr = size + "";                        //转成字符串    var index = sizeStr.indexOf(".");                    //获取小数点处的索引    var dou = sizeStr.substr(index + 1 ,2)            //获取小数点后两位的值    if(dou == "00"){                                //判断后两位是否为00，如果是则删除00        return sizeStr.substring(0, index) + sizeStr.substr(index + 3, 2)    }    return size;}