如何使用lodash链接功能? [英] How do you chain functions using lodash?

问题描述

我有一个看起来像的对象

I have an object that looks like

var foundUser = {
    charData: []
}

然后我使用mysql从数据库中加载对象，然后调用

which then I load an object from a database using mysql and then I call

_.assignIn(foundUser, rows[0]);

但是我得到了一些我不需要的额外属性(使用select无法解决此问题)

But I get a few extra properties that I don't need (this isn't solvable by using select)

所以我打电话

foundUser = _.omit(foundUser, ['blah']);

但是如果我能做的话会很好

But it would be nice if I could just do

_.assignIn(foundUser, rows[0]).omit(rows[0], ['blah']);

但这会引发错误，是我做错了还是有其他方法可以完成?

But that throws an error, am I doing it wrong or is there another way this can be done?

推荐答案

要与lodash链接，首先必须包装对象:

To chain with lodash, you first have to wrap the object:

_(foundUser).assignIn(rows[0]).omit(['blah']).value();

进一步澄清:

_创建一个lodash对象，该对象允许隐式方法链接.隐式方法链接意味着在某些情况下它可能返回一个原始值，在其他情况下，它可能会返回一个lodash对象，您需要通过调用.value()对其进行拆包.

The _ creates a lodash object which allows for implicit method chaining. Implicit method chaining means that in certain circumstances it may return a primitive value, in others it may return a lodash object that you need to unwrap by calling .value() on it.

如果使用_.chain(...)，则将使用显式方法链创建lodash对象.结果始终是包装的值，并且始终需要通过在其上调用.value()来对其进行包装.

If you'd use _.chain(...), you'd be creating a lodash object with explicit method chaining. The result is always a wrapped value and always needs to be unwrapped by calling .value() on it.

要获取更多参考，请参见文档链接:

For further reference here are the links to the documentation:

Lodash中的显式链接

Lodash中的隐式链接

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