替代百万IF语句 [英] Alternative to a million IF statements

问题描述

使用JavaScript我将网页中的名称拉出来并以某种方式将它们串在一起（可能与数组一起）。一旦我将所有名称收集在一起，我需要创建另一个字符串，该字符串提供名称的所有电子邮件地址。电子邮件地址不在网页上，所以我必须以某种方式在我的脚本中列出每个可能的thisName = thisEmail。我打算通过制作一个无数的if语句来解决这个问题，但我认为必须采用更有效的方式。有什么建议吗？

Using JavaScript I am pulling names out of webpage and stringing them together somehow (probably going with an array). Once I gather all the names together I need to make another string that gives all the email addresses of the names. The email addresses are not on the webpage so I will have to list every possible thisName=thisEmail in my script somehow. I was about to approach this with making a bazillion if statements but I thought there has to be a more efficient way. Any suggestions?

var x = getElementById("names");
var name = x.InnerHTML;
var email;
if (name == 'Steve'){ email == '[e-mail]'; }
if (name == 'Bob'){ email == '[e-mail]'; }
....

推荐答案

开关声明，因为你的代码只有if-elses： - ）

A switch statement, as your code is only if-elses :-)

不，老实说。最好的办法是，如果您找到一个简单的算法来创建任何给定名称的电子邮件地址，例如

No, honestly. The best thing would be if you'd find a simple algorithm to create an email address from any given name, like

function mail(name) {
    return name.toLowerCase() + "@gmail.com";
}
var email = mail("Bob") // example usage

如果它们差异很大，您可以使用对象作为键值映射：

If they differ to much, you might use an object as a key-value-map:

var mails = {
    "Steve": "[e-mail]",
    "Bob": "[e-mail]",
    ...
}
var email = mails[name];

如果你必须确定需要使用哪种算法，你也可以将它们结合起来：

You could also combine those, if you have to determine which algorithm you need to use:

var map = [{
    algorithm: function(name) { return name+"@something"; },
    names: ["Steve", "Bob", ...]
},{
    algorithm: function(name) { return "info@"+name+".org"; },
    names: ["Mark", ...]
}];
for (var i=0; i<map.length; i++)
    if (map[i].names.indexOf(name) > -1) {
        var email = map[i].algorithm(name);
        break;
    }

或稍微简单一点：

var domains = {
    "gmail.com": ["Steve", "Bob", ...],
    "free.xxx": ["Mark", ...],
    ...
};
for (var domain in domains)
    if (domains[domain].indexOf(name) > -1)
        var email = name.toLowerCase()+"@"+domain;
        break;
    }

尝试减少要交付给客户端的数据量你可以。

Just try to reduce the amount of data to deliver to the client as much as you can.

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