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JavaScript - all possible combinations for 2D array items
9 points
In this article, we would like to show how to create combinations for 2D array items.
Simple visualisation:
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// input:2
3
[4
['a', 'b', 'c'],5
['1', '2'],6
['w', 'x', 'y', 'z']7
]8
9
10
// output:11
12
a 1 w13
a 1 x14
a 1 y15
a 1 z16
a 2 w17
a 2 x18
a 2 y19
a 2 z20
b 1 w21
b 1 x22
b 1 y23
b 1 z24
b 2 w25
b 2 x26
b 2 y27
b 2 z28
c 1 w29
c 1 x30
c 1 y31
c 1 z32
c 2 w33
c 2 x34
c 2 y35
c 2 zQuick solution:
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function detectCombinations(input, output, position, path) {2
if (position == null) {3
position = 0;4
}5
if (path == null) {6
path = [];7
}8
if (position < input.length) {9
var item = input[position];10
for (var i = 0; i < item.length; ++i) {11
var value = item[i];12
path.push(value);13
detectCombinations(input, output, position + 1, path);14
path.pop();15
}16
} else {17
output.push(path.slice());18
}19
};20
21
22
// Helper methods:23
24
function printArray(array) {25
for (var i = 0; i < array.length; ++i) {26
console.log(array[i].join(' '));27
}28
};29
30
31
// Usage example:32
33
var input = [34
['a', 'b', 'c'],35
['1', '2'],36
['w', 'x', 'y', 'z']37
];38
var output = [];39
40
detectCombinations(input, output);41
printArray(output);
