在ImmutableJS中，如何将新数组推入Map? [英] In ImmutableJS, how to push a new array into a Map?

问题描述

如何使用ImmutableJS实现以下目标:

How can I achieve the following using ImmutableJS:

myMap.get(key).push(newData);

推荐答案

您可以执行以下操作:(请参阅此 JSBin )

You can do as follows: (see this JSBin)

const myMap = Immutable.fromJS({
  nested: {
    someKey: ['hello', 'world'],
  },
});

const myNewMap = myMap.updateIn(['nested', 'someKey'], arr => arr.push('bye'));

console.log(myNewMap.toJS());
// {
//  nested: {
//    someKey: ["hello", "world", "bye"]
//  }
// }

由于myMap是不可变的，因此每当您尝试设置/更新/删除其中的某些数据时，它将返回对新数据的引用.因此，您必须将其设置为变量才能访问它(在本例中为myNewMap).

Since myMap is immutable, whenever you try to set/update/delete some data within it, it will return a reference to the new data. So, you would have to set it to a variable in order to access it (in this case, myNewMap).

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