JavaScript で文字列をブール値に変換する方法

<input type="checkbox" id="display_hidden_form1" name="display_hidden_form1" value="true">
<label for="display_hidden_form1"> Display hide form1</label><br>

<input type="checkbox" id="display_hidden_form2" name="display_hidden_form2" value="false">
<label for="display_hidden_form2"> Display hide form2</label><br>

<script>
    let myValue = document.getElementById("display_hidden_form1").value;
    let isTrueval = myValue === 'true';

    let myValue2 = document.getElementById("display_hidden_form2").value;
    let isTrueval2 = myValue2 === 'true';

    console.log({isTrueval, isTrueval2});
</script>

{isTrueval: true, isTrueval2: false}

const convertString = (word) => {
  switch (word.toLowerCase().trim()) {
    case 'yes':
    case 'true':
    case '1':
      return true;
    case 'no':
    case 'false':
    case '0':
    case null:
      return false;
    default:
      return Boolean(word);
  }
} console.log(convertString('true'));
console.log(convertString('no'));
console.log(convertString('dasdasd'));

true
false
true

let myBool = Boolean('false');

let myBool2 = !!'false';

console.log({myBool, myBool2});

{myBool: true, myBool2: true}