Code QuizIntermediate

Null and Undefined Equality Check

A missing-value guard fails because it uses strict equality against null, which never matches undefined.

Codejavascript

function greet(name) {
  if (name === null) {
    return 'Hello, guest!';
  }
  return 'Hello, ' + name + '!';
}

console.log(greet(null));       // 'Hello, guest!'
console.log(greet(undefined));  // expected 'Hello, guest!'

Why does greet(undefined) fail to return the guest message?

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