Combinations

Installation

npm install combinations

Usage

combinations(array, [min_output_array_size], [max])

• takes in an array, and outputs an array of arrays, containing all possible combinations of values in the original array.
• combinations are of all sizes: all combinations of one element, and all combinations of 2 elements, and so on
• minimum number of elements in a combination can be specified (min_output_array_size)
• maximum number of elements in a combination can be also specified
• if maximum combination value is bigger than array elements it will be overridden to the array length

Example

var combinations = require('combinations');
var myArray = ['red', 'orange', 'yellow', 'green'];
combinations(myArray); //Output:
// [ [ 'red' ], [ 'orange' ], // [ 'yellow' ], [ 'green' ], // [ 'red', 'orange' ], [ 'red', 'yellow' ],
// [ 'red', 'green' ], [ 'orange', 'yellow' ],
// [ 'orange', 'green' ], [ 'yellow', 'green' ],
// [ 'red', 'orange', 'yellow' ], [ 'red', 'orange', 'green' ],
// [ 'red', 'yellow', 'green' ], [ 'orange', 'yellow', 'green' ],
// [ 'red', 'orange', 'yellow', 'green' ] ]

Example with a minimum array size

combinations(myArray, 2);
//Output:
// [ [ 'red', 'orange' ], [ 'red', 'yellow' ],
// [ 'red', 'green' ], [ 'orange', 'yellow' ],
// [ 'orange', 'green' ], [ 'yellow', 'green' ],
// [ 'red', 'orange', 'yellow' ], [ 'red', 'orange', 'green' ],
// [ 'red', 'yellow', 'green' ], [ 'orange', 'yellow', 'green' ],
// [ 'red', 'orange', 'yellow', 'green' ] ]

Example with a minimum and maximum array size

combinations(myArray, 2, 3);
//Output:
// [ [ 'red', 'orange' ], [ 'red', 'yellow' ],
// [ 'red', 'green' ], [ 'orange', 'yellow' ],
// [ 'orange', 'green' ], [ 'yellow', 'green' ],
// [ 'red', 'orange', 'yellow' ], [ 'red', 'orange', 'green' ],
// [ 'red', 'yellow', 'green' ], [ 'orange', 'yellow', 'green' ] ]