JavaScript: Handle Function Return Values and Errors with try-catch

To capture the true/false value returned by a function and any errors thrown by the function, you can use a try-catch block in JavaScript. Here's an example:

function isEven(num) {
  if (num % 2 === 0) {
    return true;
  } else {
    return false;
  }
}

try {
  var result = isEven(4);
  console.log(result); // true
} catch (error) {
  console.log(error); // this will not be executed unless an error occurs
}

In this example, the isEven function takes a number as an argument and returns true if the number is even and false if it's odd. We then use a try-catch block to call the function with the argument 4 and store the result in the variable result. If the function executes without any errors, the value of result will be true and it will be logged to the console. If an error occurs, it will be caught by the catch block and logged to the console instead.