how to merge two json files in javascript code example

Example 1: merge objects js

/* For the case in question, you would do: */
Object.assign(obj1, obj2);

/** There's no limit to the number of objects you can merge.
 *  All objects get merged into the first object. 
 *  Only the object in the first argument is mutated and returned.
 *  Later properties overwrite earlier properties with the same name. */
const allRules = Object.assign({}, obj1, obj2, obj3, etc);

Example 2: react merge two objects

const object1 = {
  name: 'Flavio'
}

const object2 = {
  age: 35
}

const object3 = {...object1, ...object2 }