blob: 6af0ce175c968c584be84b0d41b094c45002e9e3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
## Comments
All programmers strive to make their code easy to understand, but sometimes
extra explanation is warranted. In these cases, programmers leave *comments* in
their source code that the compiler will ignore but people reading the source
code may find useful.
Here’s a simple comment:
```rust
// hello, world
```
In Rust, the idiomatic comment style starts a comment with two slashes, and the
comment continues until the end of the line. For comments that extend beyond a
single line, you’ll need to include `//` on each line, like this:
```rust
// So we’re doing something complicated here, long enough that we need
// multiple lines of comments to do it! Whew! Hopefully, this comment will
// explain what’s going on.
```
Comments can also be placed at the end of lines containing code:
<span class="filename">Filename: src/main.rs</span>
```rust
{{#rustdoc_include ../listings/ch03-common-programming-concepts/no-listing-24-comments-end-of-line/src/main.rs}}
```
But you’ll more often see them used in this format, with the comment on a
separate line above the code it’s annotating:
<span class="filename">Filename: src/main.rs</span>
```rust
{{#rustdoc_include ../listings/ch03-common-programming-concepts/no-listing-25-comments-above-line/src/main.rs}}
```
Rust also has another kind of comment, documentation comments, which we’ll
discuss in the “Publishing a Crate to Crates.io” section of Chapter 14.
|
