Transforming multi-dimensional array into grouped array of objects

Question

I have a multidimensional array as below (columns) and need it transformed into array of objects forming a grouped hierarchal structure to construct a table header.

Each values has to be nested in the order of index and also grouped. Any pointers how this can be achieved ?

var columns = [
        ["Price", "Australia", "Melbourne", "Comfort Hotel & Spa"],
        ["Price", "Costa Rica", "Tamarindo", "Summer Isle Hotel"],
        ["Stars", "Fiji", "Suva", "Crescent Resort1"],
        ["Stars", "Fiji", "Suva", "Crescent Resort2"],
    ];

//need it to be transformed into structure like this
var transformedArray = [{
    Header: 'Price',
    columns: [{
        Header: 'Australia',
        columns: [{
            Header: 'Melbourne',
            columns: [{
                Header: 'Comfort Hotel & Spa',
                value: 'Price-Australia-Melbourne-Comfort Hotel & Spa'
            }]
        }]
    }, {
        Header: 'Costa Rica',
        columns: [{
            Header: 'Tamarindo',
            columns: [{
                Header: 'Summer Isle Hotel',
                value: 'Price-Costa Rica-Tamarindo-Summer Isle Hotel'
            }]
        }]
    }]
}, {
    Header: 'Stars',
    columns: [{
        Header: 'Fiji',
        columns: [{
            Header: 'Suva',
            columns: [{
                    Header: 'Crescent Resort1',
                    value: 'Stars-Fiji-suva-Crescent Resort1'
                },
                {
                    Header: 'Crescent Resort2',
                    value: 'Stars-Fiji-suva-Crescent Resort2'
                }
            ]
        }]
    }]
}]

pilchard · Accepted Answer · 2021-01-18 18:58:07Z

1

You can use nested reduce() calls to build the structure of each object, reserving out the last element of each array to push into the innermost columns array returned by the inner reduce()

var input = [["Price", "Australia", "Melbourne", "Comfort Hotel & Spa"], ["Price", "Costa Rica", "Tamarindo", "Summer Isle Hotel"], ["Stars", "Fiji", "Suva", "Crescent Resort1"], ["Stars", "Fiji", "Suva", "Crescent Resort2"],];

const output = input.reduce((a, arr) => {
  const
    leafValue = arr.join('-'),
    leafHeader = arr.pop();

  const inner = arr.reduce((b, e) => (
    b.push({ Header: e, columns: [] }), b[b.length - 1].columns), a)

  inner.push({ Header: leafHeader, value: leafValue });
  return a;
}, [])

console.log(JSON.stringify(output, null, 2));

answered Jan 18, 2021 at 18:58

pilchard

13.1k5 gold badges14 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Transforming multi-dimensional array into grouped array of objects

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related