Array of objects to array of arrays in JavaScript

Converting an array of objects to an array of arrays is a common transformation in JavaScript. This is useful when you need to extract object values into a simpler array format for data processing or visualization.

Problem Statement

Suppose we have an array of objects like this:

const arr = [
    {"Date":"2014","Amount1":90,"Amount2":800},
    {"Date":"2015","Amount1":110,"Amount2":300},
    {"Date":"2016","Amount1":3000,"Amount2":500}
];

We need to transform this into an array of arrays containing the object values:

[
    ['2014', 90, 800],
    ['2015', 110, 300],
    ['2016', 3000, 500]
]

Using Object.values() with map()

The most concise approach uses Object.values() to extract values from each object:

const arr = [
    {"Date":"2014","Amount1":90,"Amount2":800},
    {"Date":"2015","Amount1":110,"Amount2":300},
    {"Date":"2016","Amount1":3000,"Amount2":500}
];

const result = arr.map(obj => Object.values(obj));
console.log(result);

[ [ '2014', 90, 800 ], [ '2015', 110, 300 ], [ '2016', 3000, 500 ] ]

Using a Custom Function

For more control or compatibility with older environments, you can use a traditional function:

const arr = [
    {"Date":"2014","Amount1":90,"Amount2":800},
    {"Date":"2015","Amount1":110,"Amount2":300},
    {"Date":"2016","Amount1":3000,"Amount2":500}
];

const arrify = (arr = []) => {
    const res = [];
    const { length: l } = arr;
    for(let i = 0; i < l; i++){
        const obj = arr[i];
        const subArr = Object.values(obj);
        res.push(subArr);
    }
    return res;
};

console.log(arrify(arr));

[ [ '2014', 90, 800 ], [ '2015', 110, 300 ], [ '2016', 3000, 500 ] ]

Extracting Specific Properties

If you need only specific properties in a particular order, you can specify them manually:

const arr = [
    {"Date":"2014","Amount1":90,"Amount2":800},
    {"Date":"2015","Amount1":110,"Amount2":300},
    {"Date":"2016","Amount1":3000,"Amount2":500}
];

const result = arr.map(obj => [obj.Date, obj.Amount1, obj.Amount2]);
console.log(result);

[ [ '2014', 90, 800 ], [ '2015', 110, 300 ], [ '2016', 3000, 500 ] ]

Comparison

Conclusion

Use arr.map(obj => Object.values(obj)) for the most concise solution. For specific properties or order control, use manual property access with destructuring or direct property references.