检测设备系统是否 win7 的函数

用于检测用户设备的函数，传入v

function isWin7(v) {
  const userAgent = navigator.userAgent.toLowerCase();
  let version;
  if (userAgent.includes("win")) {
         version = "Windows";
    if (userAgent.includes("windows nt 5.0")) {
         version = "Windows 2000";
    } else if (
      userAgent.includes("windows nt 5.1") ||
      userAgent.includes("windows nt 5.2")
    ) {
         version = "Windows XP";
    } else if (userAgent.includes("windows nt 6.0")) {
         version = "Windows Vista";、
    } else if (
      userAgent.includes("windows nt 6.1") ||
      userAgent.includes("windows 7")
    ) {
         version = "Windows 7";
    } else if (
      userAgent.includes("windows nt 6.2") ||
      userAgent.includes("windows 8")
    ) {
         version = "Windows 8";
    } else if (userAgent.includes("windows nt 6.3")) {
         version = "Windows 8.1";
    } else if (
      userAgent.includes("windows nt 6.2") ||
      userAgent.includes("windows nt 10.0")
    ) {
         version = "Windows 10";
    } else {
         version = "Unknown";
    }
  }
  return version === v||"Windows 7";
}