コメント
あらゆるプログラムにはコメントが必要です。Rustには何種類かのコメントがあります
Regular Comments
These are ignored by the compiler:
- Line comments: Start with
//and continue to the end of the line - Block comments: Enclosed in
/* ... */and can span multiple lines
Documentation Comments (Doc Comments) which are parsed into HTML library documentation:
///- Generates docs for the item that follows it//!- Generates docs for the enclosing item (typically used at the top of a file or module)
fn main() {
// Line comments start with two slashes.
// Everything after the slashes is ignored by the compiler.
// Example: This line won't execute
// println!("Hello, world!");
// Try removing the slashes above and running the code again.
/*
* Block comments are useful for temporarily disabling code.
* They can also be nested: /* like this */ which makes it easy
* to comment out large sections quickly.
*/
/*
Note: The asterisk column on the left is just for style -
it's not required by the language.
*/
// Block comments make it easy to toggle code on/off by adding
// or removing just one slash:
/* <- Add a '/' here to uncomment the entire block below
println!("Now");
println!("everything");
println!("executes!");
// Line comments inside remain unaffected
// */
// Block comments can also be used within expressions:
let x = 5 + /* 90 + */ 5;
println!("Is `x` 10 or 100? x = {}", x);
}