Upload notes on exception

Author: XuhuaHuang

Exception/basic.cpp

@@ -0,0 +1,79 @@
+/**
+ * @file basic.cpp
+ * @author Xuhua Huang
+ * @brief Basic exception handling example
+ * The C++ standard provides a base class specifically designed to declare objects to be thrown as exceptions
+ * and to be caught by handlers. This class is called std::exception and is defined in the <exception> header file.
+ * The std::exception class has a virtual member function called what() that returns a C-style string describing
+ * the exception. This function can be overridden in derived classes to provide more specific information about the
+ * exception.
+ *
+ * `std::bad_alloc`, `std::runtime_error` and `std::invalid_argument`
+ *
+ * @version 0.1
+ * @date 2026-04-04
+ *
+ * @copyright Copyright (c) 2026
+ *
+ */
+
+#include <iostream>
+#include <stdexcept> // for std::runtime_error and std::invalid_argument
+#include <string>
+
+class invalid_sensor_data_error_t : public std::runtime_error {
+public:
+  explicit invalid_sensor_data_error_t(const std::string& message)
+    : std::runtime_error(message) {}
+};
+
+class sensor_processor_t {
+public:
+  double process_reading(double value) const {
+    if (value < 0.0) {
+      throw invalid_sensor_data_error_t("Negative sensor value detected");
+    } else if (value > 1000.0) {
+      throw invalid_sensor_data_error_t("Sensor value exceeds safe threshold");
+    }
+    // Simulated processing
+    return value * 0.5;
+  }
+};
+
+int main() {
+  try {
+    throw 500;      //  generates the exception
+  } catch (int e) { // matches the catch block with the type of data (int) thrown
+    std::cout << "An exception occurred. We saw exception: " << e << std::endl;
+  } catch (char e) {
+    std::cout << "char exception: " << e << std::endl;
+  } catch (...) {
+    // match any type of exception and is used to handle anything not caught by any of the other catch blocks
+    std::cout << "default exception" << std::endl;
+  }
+  // After an exception is handled, execution resumes after the try-catch block,
+  // and the program continues as normal.
+  std::cout << "Program continues after handling the exception." << std::endl;
+
+  try {
+    throw std::runtime_error("Something bad happened");
+  } catch (const std::exception& e) {
+    std::cout << "An exception occurred: " << e.what() << std::endl;
+  }
+
+  sensor_processor_t processor;
+
+  constexpr double readings[] = {25.0, -5.0, 2000.0};
+  for (double value : readings) {
+    try {
+      double result = processor.process_reading(value);
+      std::cout << "Processed value: " << result << std::endl;
+    } catch (const invalid_sensor_data_error_t& e) {
+      std::cerr << "Custom exception caught: " << e.what() << std::endl;
+    } catch (const std::exception& e) {
+      std::cerr << "Standard exception caught: " << e.what() << std::endl;
+    }
+  }
+
+  return 0;
+}