JavaScript - all possible combinations for 2D array items

In this article, we would like to show how to create combinations for 2D array items.

Simple visualisation:

// input:

[
	['a', 'b', 'c'],
  	['1', '2'],
  	['w', 'x', 'y', 'z']
]


// output:

a 1 w
a 1 x
a 1 y
a 1 z
a 2 w
a 2 x
a 2 y
a 2 z
b 1 w
b 1 x
b 1 y
b 1 z
b 2 w
b 2 x
b 2 y
b 2 z
c 1 w
c 1 x
c 1 y
c 1 z
c 2 w
c 2 x
c 2 y
c 2 z

Quick solution: 

// ONLINE-RUNNER:browser;

function detectCombinations(input, output, position, path) {
    if (position == null) {
      	position = 0;
    }
    if (path == null) {
      	path = [];
    }
    if (position < input.length) {
        var item = input[position];
        for (var i = 0; i < item.length; ++i) {
            var value = item[i];
            path.push(value);
            detectCombinations(input, output, position + 1, path);
            path.pop();
        }
    } else {
      	output.push(path.slice());
    }
};


// Helper methods:

function printArray(array) {
  	for (var i = 0; i < array.length; ++i) {
  	  	console.log(array[i].join(' '));
  	}
};


// Usage example:

var input = [
	['a', 'b', 'c'],
  	['1', '2'],
  	['w', 'x', 'y', 'z']
];
var output = [];

detectCombinations(input, output);
printArray(output);

See also

1. JavaScript - all possible combinations tree for 2D array items