Boolean Coercion

Make sure you attempt the activity on your own before checking out the solution.

Instructions:

Study the JavaScript code inside of the script tags.

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Boolean Coercion</title>
</head>

<body>

  <script>
    const age = prompt('How old are you?');

    // What would we put inside of the parentheses to check if the user supplied an age?
    if () {
      alert(`You are ${age}`);
    } else {
      alert('You did not input your age');
    }

  </script>

</body>

</html>

Without using the equality comparison operator (===) what could you write inside the parentheses for the ifstatement to check if the user has supplied a value to age?

Hints:

Run the code and when prompted for an age, press enter without inputting anything and try to log the type and value of age.

Utilize console.log to check possible solutions for truthy and falsy values.

Don't try to run the code without adding a condition to the if statement. You'll get a syntax error for not having a value inside the if () { parentheses.

Solution

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Boolean Coercion</title>
</head>

<body>

  <script>
    const age = prompt('How old are you?');

    // Inside of the if statement, age is cast to a boolean
    if (age) {
      alert(`You are ${age}`);
    } else {
      alert('You did not input your age');
    }

  </script>

</body>

</html>

Boolean Coercion - Activity