如何在不循环的情况下将固定属性值插入数组中的每个对象？

Question

Is there any way I can insert a fixed value into every object inside an array? I'm able to achieve the final output by looping. Is there any way I can achieve the final output without using a for/while loop?

Programming Language used: JavaScript

Example Array:

"cars": [
    { "name":"Ford", "models":"Fiesta" },
    { "name":"BMW", "models":"X1" },
    { "name":"Fiat", "models":"Punto" }
]

Required Array : Need to add type:"diesel" to each object in the array

"cars": [
    { type:"diesel", "name":"Ford", "models":"Fiesta"  },
    { type:"diesel", "name":"BMW", "models":"X1" },
    { type:"diesel", "name":"Fiat", "models":"Punto" }
]

Answer 1

By definition you will have to loop. The only question is whether you write the loop yourself with for , or use something like forEach which loops for you.

cars.forEach(car => car.type = "diesel")

Here is a slightly more functional approach:

const addType = type => car => car.type = type;

cars.forEach(addType("diesel"))

Yes, this is a bit complicated. addType creates a function which sets the type property of whatever is passed to it to some value. So addType("diesel") is a function which adds type: "diesel" to its argument.

Or you could just loop:

for (car of cars) car.type == "diesel";

The above will mutate the original objects. To create an array of new objects with the added property:

cars.map(car => ({...car, type: diesel}))

Answer 2

You can also use map to solve your purpose.

   cars.map((obj) => {
        obj.Active = 'false';
        return obj;
    }

Answer 3

You can use Array#map .

 var automobile = { "cars": [ { "name":"Ford", "models":"Fiesta" }, { "name":"BMW", "models":"X1" }, { "name":"Fiat", "models":"Punto" } ] } var newArr = automobile["cars"].map((car) =>{ car['type'] = "diesel"; return car; }); console.log(newArr); 

Answer 4

Using forEach

var vehicle = {
  "cars": [
    { "name":"Ford", "models":"Fiesta" },
    { "name":"BMW", "models":"X1" },
    { "name":"Fiat", "models":"Punto" }
]
}


vehicle.cars.forEach((car) =>{
  car.type = "diesel";
  return car;
});
console.log(vehicle.cars);