combination of letters with three and more letters

I want to remove the single string and want to keep string with minimum length 3 and above i tried to access string with this if(result.string >= 3) but it is giving array length so i tried to access string but i cant. so please anybody who can help me

let stringCombinations = (str) => {
    let strLength = str.length;
    let result = [];
    let currentIndex = 0;
    while (currentIndex < strLength) {
      let char = str.charAt(currentIndex);
      let x;
      let arrTemp = [char];
      for (x in result) {
        arrTemp.push("" + result[x] + char);
    }
      result = result.concat(arrTemp);
      currentIndex++;
    }
    return result;
  };
  console.log(stringCombinations("BLADE"));

This is my ouput
output: (31) ["B", "L", "BL", "A", "BA", "LA", "BLA", "D", "BD", "LD", "BLD", "AD", "BAD", "LAD", "BLAD", "E", "BE", "LE", "BLE", "AE", "BAE", "LAE", "BLAE", "DE", "BDE", "LDE", "BLDE", "ADE", "BADE", "LADE", "BLADE"]


This is what I want
["BLA", "BLD", "BAD", "LAD", "BLAD", "BLE", "BAE", "LAE", "BLAE", "BDE", "LDE", "BLDE", "ADE", "BADE", "LADE", "BLADE"]