不使用删除操作符从 JavaScript 对象中删除属性

Question

I need to extract certain properties from an object and assign to a new object. In a traditional way, I can assign manually whats required from an object property to a new object's property.

Currently i am using delete operator on the original object and creating a new object.

Is there a better way to do it.

Answer 1

You could destructure an object and pick the unwanted and get the rest as result object.

It uses

• computed property name

   { [key]:_, ...result } = object; ^^^^^ 

• destructuring assignment with an

   { [key]:_, ...result } = object; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 

• Assigning to new variable names (which is not used anymore) and

   { [key]:_, ...result } = object; ^ 

• Rest in Object Destructuring

   { [key]:_, ...result } = object; ^^^ 

 var object = { a: 1, b: 2, c: 3 }, key = 'a', { [key]:_, ...result } = object; console.log(result); 

Answer 2

Using ES6 Deconstructing Operator you can do a

ler arr = [{id:1, name: foo}, {id:2, name: bar}]
arr.map({id, ...item} => {
   return item
})

Consider you want to remove id property the above code will remove the id property and returns the object containing the name property.

Answer 3

You have to create new object by copying all the properties from the old, except the one you want to remove:

 const person = {
      name: 'abc',
      age: 25
    };

    console.log(person);

    const age = 'age';

    const newPerson = Object.keys(person).reduce((object, key) => {
      if (key !== age) {
        object[key] = person[key]
      }
      return object
    }, {});

    console.log(newPerson);