Vue

HTML

<main id="app">
    
    <input type="number" id="entryValue">
    <p>This is your random string "OHJTAYUCFN"</p>
    <input type="text" v-model="userAttemptedWord" style="text-transform: uppercase" placeholder="Enter a word">
    <button class="submitWord">Submit this word</button>
</main>

Vue

new Vue({
  el: "#app",
  data: {
    stringLength: 0,
    randomStringForGame: 'OHJTAYUCFN',
    userAttemptedWord: '',
    wordExistsInWordList: '',
    wordContainsValidCharacters: '',
    wordAccepted: '',
    wordList: ['JOY', 'FUN', 'HOT', 'NOT']
  },

  methods: {
    submitWord:
      function () {
        if (checkWordExistsInList() && checkWordHasValidCharacters()) {
          this.wordAccepted = true;
        }
        else {
          this.wordAccepted = false;
        };
      }
  },

  computed: {
    splitUserAttemptedWord: function () {
      return this.userAttemptedWord.split("");
    },

    checkWordExistsInList: function () {
      word = this.userAttemptedWord;
      return this.wordListArray.includes(word);
    },

    checkWordHasValidCharacters: function () {
      splitUserCurrentWord = this.userAttemptedWord.split("");
      for (var i = 0; i <= splitUserCurrentWord.length; i++) {
        if (this.randomStringForGame.split("").includes(splitUserCurrentWord[i])) {
          return true;
        }
        else {
          return false;
        }
      }
    }

  }
});