const toObject = (arr, identifier) => arr.reduce((a, b) => ({ ...a, [b[identifier]]: b }), {});

/*
toObject(
    [
        { id: '1', name: 'Alpha', gender: 'Male' },
        { id: '2', name: 'Bravo', gender: 'Male' },
        { id: '3', name: 'Charlie', gender: 'Female' },
    ],
    'id'
)
returns
{
    '1': { id: '1', name: 'Alpha', gender: 'Male' },
    '2': { id: '2', name: 'Bravo', gender: 'Male' },
    '3': { id: '3', name: 'Charlie', gender: 'Female' },
}
*/