Example code

Learn example code in documentation.

Example code

Example code in doc comments shows the reader how to use the API. A Markdown code block starts with ```dart and ends with ```.

Each line must start with ///; so you write /// ```dart and add lines like /// square(4); below it.

dartdoc renders the code block as syntax-highlighted HTML; this clearly explains how to use the API.

An example code example

Typical usage: under /// Example: you write /// ```dart, then /// final sum = add(2, 3); and finally /// ```.

The code block should contain real working code; comments are added with //. dartdoc highlights it as-is.

Pick short, meaningful examples; long ones bloat the docs and reduce readability.

Exercise A doc comment with example code

Write int square(int n) => n * n;. Add a doc comment above it: first line /// Example:, second line /// ```dart, third line /// square(4); // 16, fourth line /// ```. In main call print(square(5)).

Show example solution

/// Example:
/// ```dart
/// square(4); // 16
/// ```
int square(int n) => n * n;

void main() {
  print(square(5));
}

Test yourself

Code block start
```
/// ____dart
```
Show answer
```
/// ```dart
```
Example code parts

```dart

Code block
///

Doc comment
// 16

Inline comment
Example:

Label
How does an example code block start?
- ```dart
- <code>
- [code]
- //code
Show answer

```dart — ```dart opens a Markdown code block.

Next lesson: Summary - Documentation

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