Javascript对象

I'm interested in this scenario, involving an angular filter.

我对这个情况很感兴趣，包括角滤波器。

I have a column returned from my database which is a boolean, I want to return from my angular filter based on that value. Simple:

我有一个从数据库返回的列，它是一个布尔值，我想根据这个值从我的角过滤器返回。简单:

function importExportFilter() {
    return function (value) {
        var conversion = {
            "true": "Import",
            "false": "Export"
        };

        return allowable[value];
    }
}

That is nice and simple, however it doesn't deal with cases where the value isn't a key in our conversion dictionary.

这很好很简单，但是它不处理在我们的转换字典中值不是键的情况。

Two ways to deal with it:

有两种处理方法:

if (conversion.hasOwnProperty(value)) {
    return conversion[value];
}

return "Unknown";

OR:

或者:

return conversion[value] === undefined ? "Unknown" : conversion[value];

Is there a way to modify the javascript object to basically allow this:

是否有一种方法可以修改javascript对象，使其基本允许:

var conversion = {
    "true": "Import",
    "false": "Export",
    "*": "Unknown"
};

where "*" is just a wildcard. It's not an exceptional circumstance where there is an unknown value so Unknown can be used whenever there is no actual value.

其中“*”只是一个通配符。在没有实际值的情况下，未知的值可以被使用，这不是一个特殊的情况。

I can't seem to think of any other interesting ways to do this. Obviously in a business environment I would always go with the first way to deal with unexpected circumstances.

我似乎想不出其他有趣的方法来做这件事。显然，在商业环境中，我总是采用第一种方法来处理意外情况。

However, I was wondering from a creative aspect, if there were any other interesting solutions to this problem?

然而，我想从创造性的角度来看，这个问题是否还有其他有趣的解决办法?

2 个解决方案

#1

You can use a logical or ||.

您可以使用逻辑或||。

It takes the first value if the value is truthy, otherwise the second value.

如果值是真实的，则取第一个值，否则取第二个值。

return conversion[value] || 'Unknown';

or another technique:

或者另一种方法:

var conversion = {
    true: "Import",
    false: "Export",
    unknown: "Unknown"
};

return conversion[x] || conversion.unknown;

2 个解决方案

#1

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