How to create a third object from two objects using the key values in JavaScript?

Suppose, we have two objects like these −

const obj1 = {
   positive: ['happy', 'excited', 'joyful'],
   negative: ['depressed', 'sad', 'unhappy']
};
const obj2 = {
   happy: 6,
   excited: 1,
   unhappy: 3
};

We are required to write a JavaScript function that takes in two such objects. The function should then use both these objects to calculate the positive and negative scores and return an object like this −

const output = {positive: 7, negative: 3};

Example

The code for this will be −

const obj1 = {
   positive: ['happy', 'excited', 'joyful'],
   negative: ['depressed', 'sad', 'unhappy']
};
const obj2 = {
   happy: 6,
   excited: 1,
   unhappy: 3
};
const findPositiveNegative = (obj1 = {}, obj2 = {}) => {
   const result ={}
   for (let key of Object.keys(obj1)) {
      result[key] = obj1[key].reduce((acc, value) => {
         return acc + (obj2[value] || 0);
      }, 0)
   };
   return result;
};
console.log(findPositiveNegative(obj1, obj2));

Output

And the output in the console will be −

{ positive: 7, negative: 3 }