如何使用 _.set 或等效方法从数组中删除元素

Question

How to remove an element using lodash/fp's set or equivalent method.

I tried

_.set({data:[1,2,3]},"data[1]", undefined)

which results in {data:[1,undefined,3]} where as I would like to get the output as {data:[1,3]}

also tried unset which results in {data:[1,empty,3]}

Answer 1

Here is a clean solution for you. The only thing you need to change is the _.isEqual(idx, 1) for whatever index that you want to remove, or even change it and use an array, if you need by using _.includes([1, 5, 10], idx) instead of the _.isEqual() functionality.

 // Your idea: _.set({data:[1,2,3]},"data[1]", undefined) // Using a simple _.reject() function: const newData = _.assign({}, myObj, { data: _.reject(myObj.data, (val, idx) => _.isEqual(idx, 1)) });

Answer 2

I solved it using a sequence of operations.

1. used get to fetch the array at the specified path.
2. used slice to get a sliced array till specified index.
3. used slice to get second array after specified index.
4. used concat to merge first and second array.
5. used set to set the array at the specified path.

    const arrayData = get(path, state);
    if (arrayData && index < arrayData.length) {
      const firstSet = slice(0, payload.index, arrayData);
      console.log("array data after slice", arrayData);
      const secondSet = slice(payload.index + 1, arrayData.length, arrayData);

      const newState = set(
        path,
        concat(firstSet, secondSet),
        state
      );
    } else {
       return {...state}
    }