C++ Arrays in Data Structures:

 

Arrays are a fundamental concept in programming, especially in C++. They allow us to store multiple values of the same type in a single variable, making data management more efficient. This guide will walk you through the basics of arrays in C++, including their syntax, usage, and common operations.​

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📦 What Is an Array?

An array is a collection of elements, all of the same type, stored in contiguous memory locations. Think of it as a row of boxes, each holding a value, and each box is identified by an index. In C++, arrays are zero-indexed, meaning the first element is at index 0.​

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🛠️ Declaring and Initializing Arrays

Declaration

To declare an array in C++, specify the data type, array name, and size:​

data_type array_name[array_size];

For example, to store marks for 5 students:​

int marks[5];

Initialization

You can initialize an array at the time of declaration:​

int marks[5] = {85, 90, 78, 92, 88};

If you omit the size, the compiler determines it based on the initializer:​W3Schools.com+8Programiz+8GeeksforGeeks+8

int marks[] = {85, 90, 78, 92, 88};

Each element can be accessed using its index:​

cout << marks[0]; // Outputs 85

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🔄 Iterating Through Arrays

Loops are commonly used to process arrays. Here's how to print all elements:​

for (int i = 0; i < 5; i++) {
    cout << marks[i] << endl;
}

In C++11 and later, you can use range-based for loops:​

for (int mark : marks) {
    cout << mark << endl;
}

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🔍 Finding Minimum and Maximum Values

To find the smallest and largest elements:​W3Schools.com+3Programiz+3YouTube+3

int smallest = marks[0];
int largest = marks[0];

for (int i = 1; i < 5; i++) {
    if (marks[i] < smallest) {
        smallest = marks[i];
    }
    if (marks[i] > largest) {
        largest = marks[i];
    }
}

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🔁 Reversing an Array

To reverse the elements of an array:​

int start = 0;
int end = 4; // For an array of size 5

while (start < end) {
    int temp = marks[start];
    marks[start] = marks[end];
    marks[end] = temp;
    start++;
    end--;
}

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🔎 Linear Search

To search for a specific value:​

int target = 90;
bool found = false;

for (int i = 0; i < 5; i++) {
    if (marks[i] == target) {
        found = true;
        break;
    }
}

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📤 Passing Arrays to Functions

Arrays are passed by reference to functions, allowing modifications to affect the original array:​

void doubleMarks(int arr[], int size) {
    for (int i = 0; i < size; i++) {
        arr[i] *= 2;
    }
}

Calling doubleMarks(marks, 5); will double each element in the marks array.​

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🧠 Summary

• Declaration: Define the type, name, and size.

• Initialization: Assign values at declaration or later.

• Access: Use indices starting from 0.

• Iteration: Use loops to process elements.

• Operations: Search, find min/max, reverse, and modify elements.

• Functions: Arrays are passed by reference.​W3Schools.com+3W3Schools.com+3Cplusplus.com+3

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📝 Practice Exercise

Create an array of 10 integers. Implement functions to:​Cplusplus.com+3Microsoft Learn+3Learn C+++3

1. Find the sum of all elements.

2. Find the average value.

3. Identify and print all even numbers.

4. Reverse the array.​

This exercise will reinforce your understanding of arrays and their manipulation in C++.​