colouredTriangles005-code-works-but-wrong-algorythm.js

let row = "RGBG";


triangle(row);

function triangle(row) {
  let prevLetter = "";
  let rowLength = row.length; // so we can calculate how many times we must execute the algorithm
  let triangle = [];
  let result = "";


  if (rowLength === 1) {
    result= row.slice(0);   
 console.log( " IF " , result);
  }
  else {
    //Calculate how many times we have to execute the algorithm
    
    for (let i = 0; i < rowLength - 1; i++) {

      prevLetter = row.slice(i, i + 2);
      result = result + calculateLastColor(prevLetter);
      result = result.slice(-1);
    console.log("ELSE:", i);
    console.log("result:" , result);
    console.log("RowLength:", rowLength);
    }
    
    
    
  }
  //console.log(triangle);
  //console.log("Result: ", result);
  console.log("ELSE:", i);
    console.log("result:" , result);
    console.log("RowLength:", rowLength);
return result;


}


function calculateLastColor(prevRow) {

  let lastTwoDigits = prevRow.slice(-2); // The slice in this case, will select the last two digits in a string. If we put -1 will only select the last one etc  https://stackoverflow.com/questions/3884632/how-to-get-the-last-character-of-a-string

  if (lastTwoDigits.charAt(0) == lastTwoDigits.charAt(1)) return lastTwoDigits.charAt(0);
  else {

    switch (lastTwoDigits) {
      case 'RG': return "B";
        break;

      case 'RB': return "G";
        break;

      case 'BR': return "G";
        break;

      case 'BG': return "R";
        break;

      case 'GR': return 'B';
        break;

      case 'GB': return 'R';
        break;

    }


  }
}