CIPAD 38 2e partie: Les tableaux informatiques

Introduction

This tutorial focuses on understanding and using arrays in programming, specifically within the context of Arduino. Arrays, also known as tables or lists, allow you to store multiple values under a single variable name, which is essential for organizing data efficiently. Whether you are a beginner or looking to refresh your knowledge, this guide will help you grasp the fundamentals of arrays in programming.

Step 1: Understanding Arrays

• An array is a collection of elements stored in a single variable.
• Elements in an array are stored in consecutive memory locations.
• Arrays are categorized as:
  • Unidimensional (one-dimensional)
  • Monodimensional
  • Simple or linear arrays

Practical Tip

Think of an array as a row of boxes, where each box contains a piece of data that you can access using the box's position (index).

Step 2: Declaring an Array

• To declare an array in Arduino, use the following syntax:

dataType arrayName[arraySize];

• Example of declaring an integer array with five elements:

int myArray[5];

Practical Advice

• Choose an appropriate data type based on the type of values you plan to store (e.g., int, float, char).
• The array size must be a constant value, as it defines how many elements the array can hold.

Step 3: Initializing an Array

• You can initialize an array at the time of declaration using curly braces:

int myArray[5] = {10, 20, 30, 40, 50};

• If the size is omitted, the compiler determines it based on the number of initializing values:

int myArray[] = {10, 20, 30, 40, 50};

Common Pitfalls

• Ensure that the number of initializing values does not exceed the declared size of the array to avoid errors.

Step 4: Accessing Array Elements

• Access elements in an array using their index, which starts from 0:

int firstElement = myArray[0]; // Accesses the first element (10)

• Modify elements similarly:

myArray[1] = 25; // Changes the second element from 20 to 25

Practical Tip

Use loops to iterate over array elements for processing large datasets efficiently. For example, you can use a for loop to print all elements:

for (int i = 0; i < 5; i++) {
    Serial.println(myArray[i]);
}

Step 5: Using Arrays in Functions

• Arrays can be passed to functions for better code organization. Here is how to define a function that takes an array as a parameter:

void printArray(int arr[], int size) {
    for (int i = 0; i < size; i++) {
        Serial.println(arr[i]);
    }
}

Real-World Application

This technique is useful when dealing with sensor data, where you can store readings in an array and process them collectively.

Conclusion

Understanding arrays is fundamental to programming with Arduino. They allow you to manage data efficiently and are essential for more complex programming tasks. Practice declaring, initializing, accessing, and using arrays in functions to solidify your understanding. For further exploration, consider creating projects that utilize multiple arrays or delve into multidimensional arrays for more complex data organization.