如何在字符串中搜索多个值

三个选项:

1. 地图对象

2. 数组查找

3. switch

细节:

1. 你可以使用一个查找映射对象:

   // In a common declarations area
   var weather = {
       "thunderstorm": true,
       "fog": true,
       "hail": true,
       "heavy_snow": true,
       "rain": true,
       "sleet": true,
       "snow": true
   };
   // Where you want the check
   if (weather[filenameTmp]) {
       document.getElementById("twilightBG").style.display = "none";
   }
   

   请注意，如果您愿意，可以内嵌:

   if ({ "thunderstorm": true, "fog": true, "hail": true, "heavy_snow": true, "rain": true, "sleet": true, "snow": true }[filenameTmp]) {
       document.getElementById("twilightBG").style.display = "none";
   }
   

   请注意，如果filenameTmp具有"toString", "valueOf"或类似的值，您将从中获得假阳性。如果你使用的是真正支持es5的引擎，你可以通过使用builder函数获得纯映射(没有toString之类的对象):

   function pureMap(props) {
       var o = Object.create(null);
       var key;
       if (props) {
           for (key in props) {
               o[key] = props[key];
           }
       }
       return o;
   }
   

   :

   // In a common declarations area
   var weather = pureMap({
       "thunderstorm": true,
       "fog": true,
       "hail": true,
       "heavy_snow": true,
       "rain": true,
       "sleet": true,
       "snow": true
   });
   // Where you want the check
   if (weather[filenameTmp]) {
       document.getElementById("twilightBG").style.display = "none";
   }
   

2. 或者您可以使用数组，但搜索是线性的，而浏览器可以优化上面的地图查找:

   // In a common declarations area
   var weather = [
       "thunderstorm",
       "fog",
       "hail",
       "heavy_snow",
       "rain",
       "sleet",
       "snow"
   ];
   // Where you want the check
   if (weather.indexOf(filenameTmp) !== -1) {
       document.getElementById("twilightBG").style.display = "none";
   }
   

   同样，可以是inline:

   if ([ "thunderstorm", "fog", "hail", "heavy_snow", "rain", "sleet", "snow" ].indexOf(filenameTmp) !== -1) {
       document.getElementById("twilightBG").style.display = "none";
   }
   

3. 还有switch选项:

   switch (filenameTmp) {
       case "thunderstorm":
       case "fog":
       case "hail":
       case "heavy_snow":
       case "rain":
       case "sleet":
       case "snow":
           document.getElementById("twilightBG").style.display = "none";
           break;
   }
   

您可以将match()方法与正则表达式一起使用

var.match(^(?:apple|pear|whatever)$/)

您可以像这样使用数组方法:

if (["thunderstorm", "fog", "hail", "heavy_snow", "haze", "sleet", "snow"].indexOf(filenameTmp) >= 0) {

if (["thunderstorm", "fog", "hail", "heavy_snow", "haze", "sleet", "snow"].indexOf(filenameTmp) !== -1) {
document.getElementById("twilightBG").style.display = "none";
}

如果将contains方法添加到Array中，检查将更加清晰。直接:

Array.prototype.contains = function(obj) { return this.indexOf(obj) > -1; };

这允许检查为:

if (['thunderstorm', 'fog', 'hail', 'heavy_snow', 'rain', 'sleet', 'snow'].contains(filenameTmp)) {
document.getElementById("twilightBG").style.display = "none";

}

使用Array并遍历每个条目。这是最有效的方法，这样它就不会在遇到任何条目时循环遍历所有条目。

function containsAny(str, substrings) {
    for (var i = 0; i != substrings.length; i++) {
        var substring = substrings[i];
        if (str == substring) {
            return true;
        }
    }
    return null;
}
var result = containsAny(filenameTmp, ["thunderstrom", "rain"]); // add values you want
if (result) {
    document.getElementById("twilightBG").style.display = "none";
}

希望能有所帮助

对于出血边缘解决方案，请使用Set。请记住，Opera和Safari目前不支持:

var weather = new Set();
weather.add("thunderstorm");
weather.add("fog");
weather.add("hail");
weather.add("heavy_snow");
weather.add("rain");
weather.add("sleet");
weather.add("snow");
if (weather.has(filenameTmp)) {
    document.getElementById("twilightBG").style.display = "none";
}

您可以使用regx:

if (filenameTmp.match(/^(thunderstorm|fog|hail|heavy_snow|rain|sleet|snow)$/)) {
    document.getElementById("twilightBG").style.display = "none";
    }

:

if (['thunderstorm', 'fog', 'hail', 'heavy_snow','rain','sleet','snow'].indexOf(filenameTmp) >= 0) {
document.getElementById("twilightBG").style.display = "none";
}

或Jquery的inArray方法:

if ($.inArray(filenameTmp, ['thunderstorm', 'fog', 'hail', 'heavy_snow','rain','sleet','snow']) >= 0) {
document.getElementById("twilightBG").style.display = "none";
}