42 lines
848 B
Markdown
42 lines
848 B
Markdown
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---
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tags:
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- C
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---
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# Arrays in C
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To declare an array in C, you must specify:
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- the data type of the variables it will store
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- the size (in square brackets)
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- the array elements (in curly brackets)
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Thus:
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```c
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int some_numbers[3] = {1, 2, 3};
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```
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> Array element individuation is the same as JavaScript, as is a standard `for`
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> loop.
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## Calculating the length of an array
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Determining the length of an array is a fairly involved process compared to
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higher-level languages. The process:
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- Get the size of the array **in bytes**
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- Divide this by the size of the first array element
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So:
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```c
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int some_numbers[3] = {1, 2, 3};
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int length = sizeof(some_numbers) / sizeof(arr[0]) // 3
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```
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What is happening under the hood:
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The array has three `int` values. The normal byte size for a single `int` is 4
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bytes (32 bits). 4 x 3 is 12. 12/4 is 3.
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