---
title: 5.3 Accessing Array Elements
description: "Individual array elements are accessed using the array name and an index enclosed in square brackets. C uses zero-based indexing, so the first element has index `0` and the last element of an array of size `n` has index `n…"
url: "https://edcret.in/docs/c-programming/arrays/5-3-accessing-array-elements/"
updated: "2026-10-27"
category: C Programming / Arrays
---

# 5.3 Accessing Array Elements

Individual array elements are accessed using the array name and an index enclosed in square brackets. C uses zero-based indexing, so the first element has index `0` and the last element of an array of size `n` has index `n - 1`.

```
#include <stdio.h>

int main(void)
{
    int numbers[] = {10, 20, 30, 40, 50};

    printf("First element: %dn", numbers[0]);
    printf("Third element: %dn", numbers[2]);
    printf("Last element: %dn", numbers[4]);

    numbers[2] = 99;

    printf("Updated third element: %dn", numbers[2]);

    return 0;
}
```

### Example Output

```
First element: 10
Third element: 30
Last element: 50
Updated third element: 99
```

### Explanation

The expression `numbers[2]` accesses the third element because indexing starts at zero.

```
numbers[2] = 99;
```

This statement replaces the existing value `30` with `99`. Array elements can be read or modified individually when the array is writable.

### Array Index Reference

For the declaration:

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

| Index | Expression | Value |
| --- | --- | --- |
| 0 | `numbers[0]` | 10 |
| 1 | `numbers[1]` | 20 |
| 2 | `numbers[2]` | 30 |
| 3 | `numbers[3]` | 40 |
| 4 | `numbers[4]` | 50 |

An index can also be an integer variable or expression:

```
int index = 3;

printf("%dn", numbers[index]);
printf("%dn", numbers[index - 1]);
```

Output:

```
40
30
```

The index expression must identify an existing array element. For an array containing five elements, valid indices are `0` through `4`. Accessing an element outside this range results in undefined behavior.