text: let value1 = 10;
  let value2 = true;
  let value3 = null;
  let value4;
             
  console.log(String(value1));   // "10"
  // console.log(String(value1.toString(2)));   // "10"
  console.log(String(value2));   // "true"
  console.log(String(value3));   // "null"
  console.log(String(value4));   // "undefined"
  