Run results for: forEach vs map by cuteLuna v2

Test name	Executions per second
✓ for loop	1,737,686 Ops/sec
map	1,725,396 Ops/sec
forEach	1,679,411 Ops/sec

map

const cuteObject = {
  [1]: [ { name: 'luna', id: 135 } ],
  [3]: [ { name: 'fat', id: 136 } ]
};

const newList = Object.keys(cuteObject).map(key => {
    const options = cuteObject[key].map(item => ({
      label: item.name,
      name: item.name,
      id: item.id,
    }));

    return {
      label: key,
      options: options,
    };
  });

forEach

const cuteObject = {
  [1]: [ { name: 'luna', id: 135 } ],
  [3]: [ { name: 'fat', id: 136 } ]
};

const newList = [];
Object.keys(cuteObject).forEach(key => {
    const options = [];
    cuteObject[key].forEach(item => {
        options.push({
            label: item.name,
            name: item.name,
            id: item.id,
        });
    });

    newList.push({
        label: key,
        options: options,
    });
});

for loop

const cuteObject = {
  [1]: [ { name: 'luna', id: 135 } ],
  [3]: [ { name: 'fat', id: 136 } ]
};

const newList = [];
const keys = Object.keys(cuteObject);
const keysLength = keys.length;

for (let i = 0; i < keysLength; i++) {
    const key = keys[i];
    const options = [];
    const items = cuteObject[key];
    const itemsLength = items.length;

    for (let j = 0; j < itemsLength; j++) {
        const item = items[j];
        options.push({
            label: item.name,
            name: item.name,
            id: item.id,
        });
    }

    newList.push({
        label: key,
        options: options,
    });
}