---
title: 5.1 Array Declaration
description: "An array is a collection of elements of the same type stored in contiguous memory locations. An array declaration specifies the element type, array name, and number of elements. ``` #include int main(void) { int numbers[5]; numbers[0] = 10; numbers[1]…"
url: "https://edcret.in/docs/c-programming/arrays/5-1-array-declaration/"
updated: "2026-10-27"
category: C Programming / Arrays
---

# 5.1 Array Declaration

An array is a collection of elements of the same type stored in contiguous memory locations. An array declaration specifies the element type, array name, and number of elements.

```
#include <stdio.h>

int main(void)
{
    int numbers[5];

    numbers[0] = 10;
    numbers[1] = 20;
    numbers[2] = 30;
    numbers[3] = 40;
    numbers[4] = 50;

    printf("%dn", numbers[0]);
    printf("%dn", numbers[2]);
    printf("%dn", numbers[4]);

    return 0;
}
```

### Example Output

```
10
30
50
```

### Explanation

The declaration:

```
int numbers[5];
```

declares an array named `numbers` that contains five elements of type `int`.

Array indexing starts at `0`. Therefore, an array containing five elements has valid indices from `0` through `4`.

| Element | Index | Assigned value |
| --- | --- | --- |
| `numbers[0]` | 0 | 10 |
| `numbers[1]` | 1 | 20 |
| `numbers[2]` | 2 | 30 |
| `numbers[3]` | 3 | 40 |
| `numbers[4]` | 4 | 50 |

An individual element is accessed using the array name followed by an index enclosed in square brackets.

```
numbers[2] = 30;
```

This statement assigns `30` to the element at index `2`.

### Array Declaration Syntax

```
data_type array_name[array_size];
```

| Component | Description | Example |
| --- | --- | --- |
| `data_type` | Type of each element | `int` |
| `array_name` | Identifier for the array | `numbers` |
| `array_size` | Number of elements | `5` |

Arrays can contain different element types by declaring separate arrays:

```
int ages[5];
float temperatures[10];
char letters[4];
double measurements[8];
```

For an ordinary array declaration, the size must be a valid array bound. A fixed-size array can use an integer constant expression:

```
#define SIZE 5

int numbers[SIZE];
```

The elements of a local array declared without an initializer have indeterminate values. They should be assigned valid values before those values are read.