07_js-debug/faq/reference-error.ts

@@ -0,0 +1,30 @@
+{
+  const firstName = 'John';
+
+  // if (firstName === John) {
+  //   // ReferenceError: John is not defined
+  //   console.log(firstName);
+  // }
+
+  // if (firstname === 'John') {
+  //   // Uncaught ReferenceError: firstname is not defined
+  //   console.log(firstName);
+  // }
+
+  if (firstName === 'John') {
+    console.log(firstName);
+  }
+
+  function greet() {
+    console.log('Hello, ' + fullName); // Cannot find name 'fullName'.
+    console.log(typeof fullName);
+  }
+
+  // greet(); // => ReferenceError: fullName is not defined
+
+  // function greet(fullName) {
+  //   console.log(`Hello, ${fullName}`);
+  // }
+
+  greet('John Wick');
+}