feat: add new tutorial on pass by value vs reference

Author: sayanee

_tutorials/code/pass-by-value-reference-arduino-esp32c3/Makefile

@@ -0,0 +1,19 @@
+BOARD?=esp32:esp32:esp32c3
+PORT?=/dev/cu.SLAB_USBtoUART*
+BUILD=build
+
+.PHONY: default lint all flash clean
+
+default: lint all flash clean
+
+lint:
+	cpplint --extensions=ino --filter=-legal/copyright,-runtime/references *.ino
+
+all:
+	arduino-cli compile --fqbn $(BOARD) --output-dir $(BUILD) ./
+
+flash:
+	arduino-cli upload --fqbn $(BOARD) --port $(PORT) --input-dir $(BUILD)
+
+clean:
+	rm -r build

_tutorials/code/pass-by-value-reference-arduino-esp32c3/pass-by-value-reference-arduino-esp32c3.ino

@@ -0,0 +1,37 @@
+// Demonstrates the difference between pass by value
+// and pass by reference in C++ using Arduino ESP32-C3
+
+void setup() {
+  Serial.begin(115200);
+  int originalValue = 5;
+
+  passByValue(originalValue);
+  Serial.print("Pass by Value: ");
+  Serial.println(originalValue);  // Outputs 5
+
+  passByReference(originalValue);
+  Serial.print("Pass by Reference: ");
+  Serial.println(originalValue);  // Outputs 10
+
+  passByReferenceWithPointer(&originalValue);
+  Serial.print("Pass by Reference with Pointer: ");
+  Serial.println(originalValue);  // Outputs 15
+}
+
+void loop() {
+}
+
+void passByValue(int value) {
+  value = 10;
+}
+
+// Linting error:
+// Is this a non-const reference?
+// If so, make const or use a pointer: int &value
+void passByReference(int &value) {
+  value = 10;
+}
+
+void passByReferenceWithPointer(int *value) {
+  *value = 15;
+}

_tutorials/pass-by-value-reference-arduino-esp32c3.md

@@ -0,0 +1,64 @@
+---
+date_updated: 2024-06-24
+layout: tutorials
+title: Pass by Value and Reference with Arduino on ESP32-C3
+dependancies:
+  - name: ESP32 Arduino
+    url: https://github.com/espressif/arduino-esp32
+chips:
+  - ESP32-C3-MINI-1-N4
+dev_board: ESP32-C3-DevKitM-1
+components:
+  - name: ESP32-C3-DevKitM-1
+    url: https://www.aliexpress.com/item/1005003989099547.html
+images:
+  prototype: blinky-esp32c3-prototype.jpg
+  console: pass-by-value-reference-arduino-esp32c3-console.png
+features:
+  - pass
+  - value
+  - reference
+  - pointer
+  - esp32c3
+video: SWIAXcH9MuA
+references:
+  - name: Schematic of ESP32-C3-DevKitM-1
+    url: https://dl.espressif.com/dl/schematics/SCH_ESP32-C3-DEVKITM-1_V1_20200915A.pdf
+  - name: Pinouts
+    url: https://docs.espressif.com/projects/esp-idf/en/latest/esp32c3/hw-reference/esp32c3/user-guide-devkitm-1.html#pin-layout
+  - name: Arduino Pins
+    url: https://github.com/espressif/arduino-esp32/blob/master/variants/esp32c3/pins_arduino.h
+prerequisites:
+  - name: Blinky with Arduino on ESP32-c3
+    url: ./blinky-arduino-esp32c3
+---
+
+This simple code the difference between pass by value and pass by reference in C++ using Arduino ESP32-C3.
+
+### Pass by Value
+
+- Syntax Simplicity: The syntax for passing by reference is straightforward and more readable compared to pointers.
+- Automatic Dereferencing: The function parameter is treated like an alias to the original variable, so you do not need to use the dereference operator (*).
+- No Null References: References must be initialized when declared, so you cannot have a null reference, which eliminates some potential runtime errors.
+
+### Pass by Reference
+
+- Syntax Simplicity: The syntax for passing by reference is straightforward and more readable compared to pointers.
+- Automatic Dereferencing: The function parameter is treated like an alias to the original variable, so you do not need to use the dereference operator (*).
+- No Null References: References must be initialized when declared, so you cannot have a null reference, which eliminates some potential runtime errors.
+
+### Pass by reference with pointers
+
+- Explicit Address Handling: You explicitly pass the address of the variable using the address-of operator (&) and use the dereference operator (*) to access and modify the value.
+- Null Pointers: Pointers can be null, providing flexibility but also the possibility of null pointer dereferencing errors.
+- C Compatibility: Pointers are compatible with C, making this method necessary when working in C or interfacing with C libraries.
+
+| Aspect                    | Pass-by-Value                       | Pass-by-Reference                  | Pass-by-Reference with Pointers    |
+|---------------------------|-------------------------------------|------------------------------------|------------------------------------|
+| **Syntax**                | `int value`                         | `int &value`                       | `int *value`                       |
+| **Usage**                 | Operates on a copy of the variable  | Direct access to variable          | Use of address-of (`&`) and dereference (`*`) operators |
+| **Modification**          | Does not affect original variable   | Affects original variable          | Affects original variable          |
+| **Initialization**        | N/A                                 | Must be initialized                | Can be null                        |
+| **Readability**           | Most readable, simplest             | More readable and less error-prone | Requires explicit pointer handling |
+| **Compatibility**         | Works in both C and C++             | C++ only                           | Works in both C and C++            |
+| **Performance**           | Copies data (may be slower for large data) | No copying, efficient            | No copying, efficient              |