如何删除具有动态数量的属性且没有eval的嵌套Javascript对象中的键？

Question

I am looking to delete a specific key from a nested Javascript object based on a list of dynamic properties. Here is an example of what I mean:

This is a sample object:

employees: [
    {
        name: "John",
        id: 1234567890,
        salary: 60000
    },
    {
        name: "Jack",
        id: 0987654321,
        salary: 55000
    }
],
location: {
    building: {
        address: "111 Main St"
    }
}

I am looking to delete the address key when I am provided an array of ['location', 'building', 'address']

When I say "dynamic" I mean that I could also be provided with an array of ['employees', 1] so I cannot rely on a set number of nested properties.

The only approach that works for me right now is to use the dreaded eval , which is not a permanent solution since the Javascript objects that I am reading are written by users.

let jsObject = ... // the object shown above
let properties = ['location', 'building', 'address']
let evalString = ''
for (let i = 0; i < properties.length; i++){
    evalString += '[\''+properties[i]+'\']'
}
eval('delete jsObject'+evalString)

What is an alternative to eval that will accomplish this same goal?

Answer 1

You can break your array into everything except the last element, get a reference to that and the call delete on the object using the last element. You can use reduce to easily build the object reference. You need to be careful with arrays because you can't use delete without leaving an empty slot — delete doesn't change the length.

Here's the basic idea:

 function deleteProp(obj, keys){ let prop = keys.pop() // get last key let c = keys.reduce((a, c) => a[c], obj) // get penultimate obj if (Array.isArray(c)) c.splice(prop, 1) // if it's an array, slice else delete c[prop] // otherwise delete } // Delete address let obj = {employees: [{name: "John",id: 1234567890,salary: 60000},{name: "Jack",id: 0987654321,salary: 55000}],location: {building: {address: "111 Main St"}}} deleteProp(obj, ['location', 'building', 'address']) console.log(obj) //Delete employee 1 obj = {employees: [{name: "John",id: 1234567890,salary: 60000},{name: "Jack",id: 0987654321,salary: 55000}],location: {building: {address: "111 Main St"}}} deleteProp(obj, ['employees', 1]) console.log(obj) //Delete employee 1 id obj = {employees: [{name: "John",id: 1234567890,salary: 60000},{name: "Jack",id: 0987654321,salary: 55000}],location: {building: {address: "111 Main St"}}} deleteProp(obj, ['employees', 1, 'id']) console.log(obj) 

Answer 2

This method accepts an object and an array of properties, and removes the inner most property as required

function remove(obj, props) {
    delete props.slice(0, -1).reduce((init, curr) => init && init[curr], obj)[[...props].pop()];
}

Answer 3

You could reduce the object by the keys and save the last key for deleting the object with that key.

 function deleteKey(object, keys) { var last = keys.pop(); delete keys.reduce((o, k) => o[k], object)[last]; return object; } var object = { employees: [{ name: "John", id: '1234567890', salary: 60000 }, { name: "Jack", id: '0987654321', salary: 55000 }], location: { building: { address: "111 Main St" } } }; console.log(deleteKey(object, ['location', 'building', 'address'])); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 4

Here is a sample that i'm sure could be trimmed down a bit but it explains each step and you should be able to see whats happening in it:

 let jsObject = { employees: [{ name: "John", id: 1234567890, salary: 60000 }, { name: "Jack", id: 0987654321, salary: 55000 } ], location: { building: { address: "111 Main St" } } }; let properties = ['location', 'building', 'address']; // we use this to traverse the object storing the parent let parent = null; // run over each property in the array for (let i = 0; i < properties.length; i++) { // check if this is the last property and we have the parent object if (i + 1 == properties.length && parent) delete parent[properties[i]]; // just delete the property from the object else if (parent === null) parent = jsObject[properties[i]] // set the initial parent else parent = parent[properties[i]] // set the parent to the property in the existing object } // log the output console.log(jsObject); 

You are going to want to throw error handling and checks to make sure you don't end up outside the object as well.

Answer 5

Navigate to the object that contains the property you want to delete, then delete it:

 let jsObject = { employees: [ { name: "John", id: 1234567890, salary: 60000 }, { name: "Jack", id: 0987654321, salary: 55000 } ], location: { building: { address: "111 Main St" } } }; let properties = ['location', 'building', 'address']; let innerMost = jsObject; for (let i = 0; i < properties.length - 1; i++) { if (typeof innerMost !== "object" || innerMost === null) { innerMost = null; break; } innerMost = innerMost[properties[i]]; }; if ( innerMost !== null && typeof innerMost === "object" && properties.length > 0 && innerMost.hasOwnProperty(properties[properties.length - 1]) ) { delete innerMost[properties[properties.length - 1]]; console.log(jsObject); } else console.log("Invalid path");