Javascript - Generating all combinations of elements in a single array (in pairs)

Question

I\'ve seen several similar questions about how to generate all possible combinations of elements in an array. But I\'m having a very hard time figuring out how to write an a

Answer 1

Although solutions have been found, I post here an algorithm for general case to find all combinations size n of m (m>n) elements. In your case, we have n=2 and m=4.

const result = [];
result.length = 2; //n=2

function combine(input, len, start) {
  if(len === 0) {
    console.log( result.join(" ") ); //process here the result
    return;
  }
  for (let i = start; i <= input.length - len; i++) {
    result[result.length - len] = input[i];
    combine(input, len-1, i+1 );
  }
}

const array = ["apple", "banana", "lemon", "mango"];    
combine( array, result.length, 0);