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Pointers & Arrays in C

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Introduction

In C programming, pointers and arrays are closely related.
An array name itself acts like a pointer to its first element.

👉 Understanding this relationship is very important for efficient programming.

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Relationship Between Pointers & Arrays

👉 Array name = address of first element

int arr[3] = {10, 20, 30};

👉 arr is same as &arr[0]

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Using Pointer with Array

#include <stdio.h>

int main() {
    int arr[] = {10, 20, 30};
    int *ptr = arr;

    printf("%d\n", *ptr);       // arr[0]
    printf("%d\n", *(ptr + 1)); // arr[1]
    printf("%d\n", *(ptr + 2)); // arr[2]

    return 0;
}

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Output

10
20
30

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Accessing Array Elements

👉 Two ways:

arr[n]  // normal way
*(ptr + n)  // pointer way

👉 Both are same

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Example: Loop Using Pointer

#include <stdio.h>

int main() {
    int arr[] = {5, 10, 15, 20};
    int *ptr = arr;
    int i;

    for (i = 0; i < 4; i++) {
        printf("%d ", *(ptr + i));
    }

    return 0;
}

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Output

5 10 15 20

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Pointer Arithmetic with Arrays

👉 Pointer moves based on data type size

ptr + 1  // moves to next element

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Array as Pointer Example

#include <stdio.h>

int main() {
    int arr[] = {1, 2, 3};

    printf("%d\n", arr[0]);
    printf("%d\n", *(arr + 0));

    return 0;
}

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Output

1
1

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Comparison Table

Feature	Array	Pointer
Meaning	Collection of elements	Stores address
Access	arr[n]	*(ptr + n)
Flexibility	Fixed size	Flexible

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Important Notes

• Array name cannot be changed
• Pointer can be reassigned
• Both use contiguous memory

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Common Mistakes

• ❌ Confusing array and pointer
• ❌ Wrong pointer arithmetic
• ❌ Out-of-bounds access
• ❌ Misusing * operator

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Pro Tips

• ✔ Practice pointer + array problems
• ✔ Use pointers for efficient coding
• ✔ Understand memory layout
• ✔ Learn with examples

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Conclusion

Pointers and arrays are deeply connected in C. Understanding this concept helps in writing efficient and optimized programs.

Master this to become strong in C programming.

👉 This article is part of Dharani Tech Edu Hub — where learning programming is made simple and practical.