test1.md

Arrays in C++

Aim

To discuss arrays, their functions, operations, and implementation.

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What is an Array?

An array is a collection of similar types of data.
This means every element in an array must be of the same data type.

• Array is a linear data structure
• Array is a non-primitive data type
• Stores data in sequential and contiguous memory locations
• Elements are accessed using index values
• Index starts from 0
• For size n, last index is n-1
• Arrays have fixed size (can simulate dynamic behavior)

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Applications

• Used in building complex data structures

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Code Implementation

#include <iostream>
using namespace std;

int main(int argc, char *argv[])
{
    // Declaration of array of size 10
    int array[10];

    // Providing elements at declaration time
    /*
    int n = 2;
    int array1[n] = {2, 4};
    ERROR: Variable-sized object can't be created
    (Compile-time error in standard C++)
    */

    const int n = 2;
    int array1[n] = {2, 4};

    // Printing uninitialized array element
    cout << "array is: " << array[0] << endl;

    // Method 1: Access using indices
    cout << "\nPrinting array1 using indices separately!" << endl;
    cout << "array1[0]: " << array1[0] << endl;
    cout << "array1[1]: " << array1[1] << endl;

    // Method 2: Using for loop
    cout << "\nPrinting array1 using for-loop" << endl;
    for (int i = 0; i < n; i++)
    {
        cout << "array1[" << i << "]: " << array1[i] << endl;
    }

    // Method 3: Using for-each loop
    cout << "\nPrinting array1 using for-each loop" << endl;
    for (int x : array1)
    {
        cout << "--> " << x << endl;
    }

    return 0;
}

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Notes

• Accessing uninitialized array elements may give garbage values
• Standard C++ does not allow variable-sized arrays
• Some compilers like GCC may allow it as an extension

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