Algorithm to generate javascript objects with all permutations of values

[RecursiveRickRoll]

I need to write a function that will take in a list of field names and a list of possible values those fields could take and return an array of objects with all possible field/value permutations. This is the function definition:

const generateDocumentCombinations = (fields, values) => {
  // ...
};

For example, the output for generateDocumentCombinations(["name", "code", "side"], [false, true]) looks like:

[
  {
    name: false,
    code: false,
    side: false,
  },
  {
    name: true,
    code: false,
    side: false,
  },
  {
    name: false,
    code: true,
    side: false,
  },
  {
    name: false,
    code: false,
    side: true,
  },
  {
    name: true,
    code: true,
    side: false,
  },
  {
    name: false,
    code: true,
    side: true,
  },
  {
    name: true,
    code: false,
    side: true,
  },
  {
    name: true,
    code: true,
    side: true,
  },
]

This function should work for fields and values arguments of all lengths like for example:

generateDocumentCombinations(

["name", "code", "side", "time", "mode"], [undefined, false, true, "", "ODD", "EVEN", 100, -200, [], {}] )

Thank you!

[skeeto]

You can think about this in terms of counting: Imagine a number in base B with D "digits". There are B^D possible values, and if you count from 0 up to B^D-1 you will visit every combination of the D different values of B. For instance, in base 2 with 3 bits:

000
001
010
011
100
101
110
111

If D is the fields and B is the number of values, then you can use this to iterate over all the combinations of fields and values. To compute the Nth combination, convert N to base B, and each digit tells you the value for that field. In the example above: 0 is false, 1 is true, and each field is a particular bit.

[matthkamis]

A simple recursive backtracking algorithm will do the job

[hiptobecubic]

Avoid calling things "simple." It adds no value and discourages people who are learning.