bigOquadratic.js

// read an array of array
function readArrayOfArray() {
    // This is an array of arrays.
    // It is a little easier to read like this:
    var arrayNumberFruit = [
        [1, 'Orange'],
        [2, 'Banana'],
        [3, 'Apple'],
        [4, 'Mango']
    ];

    arrayNumberFruit.forEach(function (items) {

        // will display [1, 'Orange'], [2, 'Banana'],...
        console.log('Items in the array are: ', items); 

        items.forEach(function (number) {

            // will display 1, Orange, 2, Banana, 3 ......
            console.log('Numbers in the array are: ', number); //
            
        });     
    });
}

// **********************************************************************************
// - In this case the run time of readArrayOfArray is quadratic: O( n²)
// - the method goes as O(N*N) or O(N²), because every time you increase the number 
// - of items in the array of array, the computation effort or time will increase as 
// - the square of the number of points.
// **********************************************************************************