merge function 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: array merge in javascript

function mergeArrays(arr1, arr2) {
  return Array.from(new Set(arr1.concat(arr2).sort((a,b) => (a-b))));
}

Example 3: react merge two objects

const object1 = {
  name: 'Flavio'
}

const object2 = {
  age: 35
}

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

Example 4: javascript object shallow merge

var obj1 = {
  foo: {
    prop1: 42,
  },
};

var obj2 = {
  foo: {
    prop2: 21,
  },
  bar: {
    prop3: 10,
  },
};

var result = {
  foo: {          // `foo` got overwritten with the value of `obj2`
    prop2: 21,
  },
  bar: {
    prop3: 10,
  },
}