版本号比较

注释这段是请教了百度写的方法：

/*var version1 = "2.0.3",
          version2 = "3.0.5";

          version1 = version1.replace(/\./g,'');
          version2 = version2.replace(/\./g,'');
          console.log(version1);
          console.log(version2);
          console.log(version2>version1);*/


  /*function compare_version(currentVersion, freshVersion){//currentVersion:当前所装的APP版本号；freshVersion：最新版本的APP的版本号
    currentVersion = currentVersion.replace(/\./g,'');
    currentVersion = parseInt(currentVersion);


    freshVersion = freshVersion.replace(/\./g,'');
    freshVersion = parseInt(freshVersion);
    console.log(currentVersion);
    console.log(freshVersion);
    // 这里的currentVersion和freshVersion，一定要用字符串比较的方式
    if(currentVersion < freshVersion){
      return true;
    }else{
      return false;
    }
  }

  var android = compare_version("0.9.64", "0.10.67");
  var ios = compare_version("0.9.15","0.10.18");
  if(android){
    console.log('android:' + android+"。去下载新版本。。。");
  }else{
    console.log('android:' + android + "已经是最新版本");
  }

  if(ios){
    console.log('ios:' + ios+"。去下载新版本。。。");
  }else{
    console.log('ios:' + ios + "已经是最新版本");
  }*/

下面这段是我借鉴上面的，然后请教了iOS 10和Android工程师，他们的版本会出现的格式，下面的方法应该是把他们会出现的版本号的格式囊括进去了，欢迎各位童鞋拍砖！

/*-----------------------------所向披靡的判断版本号大小------------------------------------*/
function compare(num1, num2) {
  var temp1 = parseInt(num1);
  var temp2 = parseInt(num2);
  if (temp1 < temp2) {
    return -1;
  } else if (temp1 == temp2) {
    return 0;
  } else {
    return 1;
  }
}

function compare_version(currentVersion, freshVersion) { //currentVersion:当前所装的APP版本号；freshVersion：最新版本的APP的版本号
  var currentVersionArray = currentVersion.split('.');
  var freshVersionArray = freshVersion.split('.');
  console.log('currentVersionArray: ' + currentVersionArray);
  console.log('freshVersionArray: ' + freshVersionArray);
  var maxLen = currentVersionArray.length;
  if (currentVersionArray.length < freshVersionArray.length) {
    maxLen = freshVersionArray.length;
    var which = freshVersionArray.length - currentVersionArray.length;
    if (which > 0) {
      for (var i = which; i > 0; i--) {
        currentVersionArray.push("0");
      }
    }

  } else if (currentVersionArray.length > freshVersionArray.length) {
    maxLen = currentVersionArray.length;
    var which = currentVersionArray.length - freshVersionArray.length;
    if (which > 0) {
      for (var i = which; i > 0; i--) {
        currentVersionArray.push("0");
      }
    }
  }
  for (var i = 0; i < maxLen; i++) {
    var temp1 = compare(parseInt(currentVersionArray[i]), parseInt(freshVersionArray[i]));
    if (temp1 == 0) {
      if (i == currentVersionArray.length - 1) {
        return true;
      }
    } else if (temp1 == 1) {
      return true;
    } else if (temp1 == -1) {
      return false;
    }
  }
}


/*------------用法（测试）---------------*/
console.log('这是Android的版本比较-------------------------------------');
var android = compare_version("1.32", "1.32");


console.log('这是ios的版本比较-------------------------------------');
var ios = compare_version("0.10.18", "0.10.18");

if (!android) {
  console.log('android:' + android + "。去下载新版本。。。");
} else {
  console.log('android:' + android + "已经是最新版本");
}

if (!ios) {
  console.log('ios:' + ios + "。去下载新版本。。。");
} else {
  console.log('ios:' + ios + "已经是最新版本");
}