Get all substrings of a string in JavaScript

I have the following function to get all of the substrings from a string in JavaScript. I know it’s not correct but I feel like I am going about it the right way. Any advice would be great.

 var theString     = 'somerandomword',
     allSubstrings = []; 

getAllSubstrings(theString);

function getAllSubstrings(str) {

  var start = 1;

  for ( var i = 0; i < str.length; i++  ) {

     allSubstrings.push( str.substring(start,i) ); 

  }

} 

console.log(allSubstrings)

Edit: Apologies if my question is unclear. By substring I mean all combinations of letters from the string (do not have to be actual words) So if the string was ‘abc’ you could have [a, ab, abc, b, ba, bac etc…] Thank you for all the responses.

Answer

You need two nested loop for the sub strings.

function getAllSubstrings(str) {
  var i, j, result = [];

  for (i = 0; i < str.length; i++) {
      for (j = i + 1; j < str.length + 1; j++) {
          result.push(str.slice(i, j));
      }
  }
  return result;
}

var theString = 'somerandomword';
console.log(getAllSubstrings(theString));

.as-console-wrapper { max-height: 100% !important; top: 0; }