what are comments in Rust language? How do you write a comments in Rust?
Comments are description text about line or block of a code.
Generally Comments are for programmers not for Rust interpreter. At runtime, These are ignored by Rust.
In Rust, You can write a comments in different following ways
- Single line comments
- Multi Line comments
- Documentation commands
It is always good practise to add Comments to the below blocks or lines of code
- Classes description
- before method declaration
- Any complex logic code
- documentation comments
Single Line comments in Rust
These also called inline comments.
- It always starts with double slashes (// ) symbol character and ends with line break.
- There is an space after a pound symbol
- an string of text begins with # symbol are ignored by Rust compiler.
- It is an description or piece of text for single line of code.
- These comments are not required at starts in begin of line, but also can write in middle or end of line Syntax:
// This is single line comments in Rust file
Example
hello.rc
// Hello World application
fn main() {
println!("Hello World app");
}
Learned single line comments, How do you write a multi line comments
Multi line comments
These comments written in multiple line and also called block comments. Hello World program is a first step to learn any programming language Steps to write a Hello World First program code.
Here is a way we can write a multi line comments with #\ symbol. Each line starts with #\ character.
// multi line comments 1
// multi line comments 2
// multi line comments 3
Rust provides special syntax to write a block level comments
// This comment is a multi line comment 1
// This comment is a multi line comment 2
// This comment is a multi line comment 3
This allows you to write a multiple lines of code and ignored by compiler.
- Each line starts with backslash(
//
) in multiple lines
Block level comments in Rust Example:
// Hello world sample program
// Basic program to print hello world to console
// First code to write in Rust programming language
fn main() {
println!("Hello World app");
}
Conclusion
You learned different types of comments in Rust
- single line comments (
//
) - Multiple line comments (Each line begins with
//
)