Comments in programming languages are used to document the programs. Comments are non-executable and are used to explain the code written in the program. Different programming languages have different syntax for writing the comments in the program. Let’s have a look at a few of them.
Table 1: Languages and Comment Syntax Examples
| Language |
Comment Syntax |
| HTML |
<!-- comment --> |
| XML |
<!-- comment --> |
| CSS |
/* comment */ |
| JavaScript |
// single-line
/* multi-line */ |
| TypeScript |
// single-line
/* multi-line */ |
| Java |
// single-line
/* multi-line */
/** doc */ |
| PHP |
// single-line
# single-line
/* multi-line */ |
| SQL |
-- single-line
/* multi-line */
# (MySQL) |
| Python |
# single-line |
| Ruby |
# single-line
=begin / =end |
| Elixir |
# single-line |
| R |
# single-line |
| Kotlin |
// single-line
/* multi-line */ |
| Scala |
// single-line
/* multi-line */ |
| Rust |
// single-line
/* multi-line */
/// doc |
| C |
// single-line
/* multi-line */ |
| C++ |
// single-line
/* multi-line */ |
| C# |
// single-line
/* multi-line */
/// doc |
| Go |
// single-line
/* multi-line */ |
| Swift |
// single-line
/* nested multi-line */ |
| Bash / Shell |
# single-line |
Table 2: Comment Syntax Examples and Languages
| Comment Syntax |
Languages |
<!-- --> |
HTML, XML |
/* */ |
CSS, JavaScript, TypeScript, Java, PHP, SQL, Kotlin, Scala, Rust, C, C++, C#, Go, Swift |
// |
JavaScript, TypeScript, Java, Kotlin, Scala, Rust, C, C++, C#, Go, Swift |
# |
Python, Ruby, Elixir, R, PHP, Bash, SQL (MySQL) |
-- |
SQL |
=begin / =end |
Ruby |
/** */ |
Java, PHP, JavaScript (Doc comments) |
/// |
Rust, C# |
