Get column in array of arrays

Below is a quick example i think:

var column_number = 2;
var column = [];
for(var i=0; i<9; i++) {

    var value = matrix[i][column_number];
    column.push(value);   

}

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));