You can do it with .map(). Immagine a fetch of database rows.

With arrow function

To have a reusable arrayColumn(array, column) function:

const array = [
    {id: 1, name: 'foo'},
    {id: 2, name: 'bar'},
];
const arrayColumn = (array, column) => {
    return array.map(item => item[column]);
};
const names = arrayColumn(array, 'name');
console.log(names);

Or you can use .map directly:

const array = [
    {id: 1, name: 'foo'},
    {id: 2, name: 'bar'},
];
const names = array.map(item => item.name);
console.log(names);

Before ES6 (2015)

var array = [
    {id: 1, name: 'foo'},
    {id: 2, name: 'bar'},
];
function arrayColumn(array, columnName) {
    return array.map(function(value,index) {
        return value[columnName];
    })
}
var names = arrayColumn(array, 'name');
console.log(names);

Taking a column is easy with the map function.

// a two-dimensional array
var two_d = [[1,2,3],[4,5,6],[7,8,9]];

// take the third column
var col3 = two_d.map(function(value,index) { return value[2]; });

Why bother with the slice at all? Just filter the matrix to find the rows of interest.

var interesting = two_d.filter(function(value,index) {return value[1]==5;});
// interesting is now [[4,5,6]]

Sadly, filter and map are not natively available on IE9 and lower. The MDN documentation provides implementations for browsers without native support.

The “fastest” in terms of “least code” would probably be Array.prototype.map:

const getColumn = (anArray, columnNumber) =>
    anArray.map(row => row[columnNumber]);

const getColumn = (anArray, columnNumber) =>
    anArray.map(row => row[columnNumber]);


const arr = [
    [1, 2, 3, 4],
    [5, 6, 7, 8],
    [9, 10, 11, 12],
];

console.log(getColumn(arr, 0));

You could iterate though the data array and add key & value to each element.

data[0]["foo"] = bar; // this can be useful if the key is not constant

or

data[0].foo = "bar"