小伙伴们在工做中会遇到这样的场景:
有一组变量的值是根据其余某个值来改变的,也就是一一对应,好比:编码
var cityCode = "城市区号", cityName = "城市名称", university = "最高学府", province = "所属省份";
城市区号是具备惟一性的,而另外三个值和城市区号是已具备关联性的。若是城市编号不肯定,但我们就得作判断,通常有if...else,switch...case,以下:code
if( cityCode == "0755") { cityName = "深圳"; university = "深圳大学"; province = "广东省"; } else if( cityCode == "010") { cityName = "北京"; university = "北京大学"; province = "北京市"; } else if( cityCode == "027") { cityName = "武汉"; university = "武汉大学"; province = "湖北省"; }
或者:ci
switch (cityCode) { case "0755" : cityName = "深圳"; university = "深圳大学"; province = "广东省"; break; case "010" : cityName = "北京"; university = "北京大学"; province = "北京市"; break; case "027" : cityName = "武汉"; university = "武汉大学"; province = "湖北省"; break; }
还有一种方式:it
cityName = {"0755" : "深圳", "010" : "北京", "027" : "武汉"}[cityCode] || "没有定义"; university = {"0755" : "深圳大学", "010" : "北京大学", "027" : "武汉大学"}[cityCode] || "没有定义"; province = {"0755" : "广东省", "010" : "北京市", "027" : "湖北省"}[cityCode] || "没有定义";
相比上面两种,这种方式的可读性可能稍微差了那么一点点,但是简洁了许多。
但仍是重复了一些,根据城市编码取了三个变量的值,结果每取一次,就要要写一次城市编码,反而不那么简洁了。变量
最后一种方式:vi
var cityMode = { "0755" : { cityCode : "0755", cityName : "深圳", university : "深圳大学", province : "广东省" }, "010" : { cityCode : "010", cityName : "北京", university : "北京大学", province : "北京市" }, "027" : { cityCode : "027", cityName : "武汉", university : "武汉大学", province : "湖北省" } }; cityName = cityMode[cityCode].cityNanme; university = cityMode[cityCode].university; province = cityMode[cityCode].province;
这种方式,应该也仍是不错的,可读性强,但貌似写的代码多了一点。co
以上,欢迎各位朋友指正,也但愿能看到更好更简洁的写法。cas