js换算字节大小

export function changeSize(limit) {
  var size = "";
  if (limit < 1 * 1024) {
    //小于0.1KB，则转化成B
    size = limit.toFixed(2) + "B";
  } else if (limit < 1 * 1024 * 1024) {
    //小于0.1MB，则转化成KB
    size = (limit / 1024).toFixed(2) + "KB";
  } else if (limit < 1 * 1024 * 1024 * 1024) {
    //小于1GB，则转化成MB
    size = (limit / (1024 * 1024)).toFixed(2) + "M";
  } else {
    //其他转化成G
    size = (limit / (1024 * 1024 * 1024)).toFixed(2) + "G";
  }
  var sizeStr = size + "";
  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") {
    return sizeStr.substring(0, index) + sizeStr.substr(index + 3, 2);
  }
  return size;
}