Filtering List By First Letter

Question

I'm having a bit of trouble filtering my list. I want to filter it to where it checks the first letter of a word the user inputs and if that first letter is the same as the letter from the lettera list.

function checkWords {
  var wordsCreated = getText("Input");
  for (var i = 0; i < letters.length; i++) {
     var firstLetter = letters [i].substring(0,1);
     firstUserLetter = wordsCreated.substring(0,1);
     if (firstLetter==firstUserLetter) {
      // uses appendItem() to add a new item to the word list
      appendItem(guessedList, getText("Input"));
      setProperty("Input", "text", "");
      setText("Output", wordList.join("\n"));
      updateScore();
      }
  }
}

I tried everything but I can't seem to figure out why it's not filtering it to where it only adds the word to the list if the first letter of it corresponds with the random letter.

Answer 1

var letters = ["a","b","c","d","e","f","g"];
var button = document.querySelector("button");
var resultArray = [];
button.addEventListener("click", function (evt) {
  var val = document.querySelector("input").value;
  let letter = letters[Math.floor(Math.random()*letters.length)];
  console.log("Random letter chosen was " + letter);
  if(val.charAt(0) === letter){
    resultArray.push(val);
  }
  console.log("Result list is: " + resultArray);
});

<input type="text" size="10">
<button>submit</button>