Java Script - Objects

const json = {
  "name": "John Doe",
  "age": 30,
  "city": "New York"
};

const keys = Object.keys(json);

console.log(keys); // ["name", "age", "city"]

Here are some ways to get all the keys from an array of objects in JavaScript:

// Using Object.keys()

const objects = [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }];

const keys = Object.keys(objects[0]);

console.log(keys); // ['name', 'age']

// Using for...in loop

const objects = [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }];

const keys = [];

for (const object of objects) {
  for (const key in object) {
    keys.push(key);
  }
}

console.log(keys); // ['name', 'age']

// Using Array.prototype.map()

const objects = [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }];

const keys = objects.map(object => Object.keys(object));

console.log(keys); // [['name', 'age'], ['name', 'age']]