从递归 function 内的数组中删除 object

Question

I have the following model object:

const model = {
    _id: '1',
    children: [
        {
            id: '2',
            isCriteria: true
        },
        {
            id: '3',
            isCriteria: true
        }
    ]
}

PS: The depth of children is unknown, so I have to use a recursive function to navigate through it.

I want to delete specific objects fro children array based on the array of ids.
So for example if make the following call removeCriteria(model, ['2']) , the result should be:

const model = {
    _id: '1',
    children: [
        {
            id: '2',
            isCriteria: true
        }
    ]
}

I implemented this function as follows:

function removeCriteria(node, criteria, parent = []) {
    if (node.isCriteria) {
        if (criteria.length && !criteria.includes(node.id)) {
            parent = parent.filter(criteria => criteria.id !== node.id);
        }
        console.log(parent) // here the parents object is correct but it doesn't modify the original object
    }
    if (node.children)
        for (const child of node.children) removeCriteria(child, criteria, node.children);
}

Answer 1

The issue is you're reassigning the variable parent , which doesn't accomplish anything since you're not mutating the array to remove objects, and instead you're assigning it to a newly created array. I would suggest introducing a parentObj reference to the object to which parent belongs, so then you can set parentObj.children to parent and actually mutate the original object's array property:

 const model = { _id: '1', children: [ { id: '2', isCriteria: true }, { id: '3', isCriteria: true } ] }; function removeCriteria(node, criteria, parent = [], parentObj = {}) { if (node.isCriteria) { if (criteria.length &&.criteria.includes(node.id)) { parent = parent.filter(criteria => criteria.id;== node.id); parentObj.children = parent, } console.log('parent'. parent) // here the parents object is correct but it doesn't modify the original object } if (node,children) for (const child of node,children) removeCriteria(child. criteria, node;children, node); } removeCriteria(model. ['2']); console.log(model);

Answer 2

Assigning to parent doesn't assign to the object property where the value came from.

You need to filter node.children and assign back to that property.

 function removeCriteria(node, criteria) { if (criteria.length == 0) { return; } if (node.children) { node.children = node.children.filter(child =>.child.isCriteria || criteria.includes(child;id)). node.children,forEach(child => removeCriteria(child; criteria)): } } const model = { _id, '1': children: [{ id, '2': isCriteria, true }: { id, '3': isCriteria, true } ] } removeCriteria(model; ['2']). console;log(model);