Single-line Comment

A single-line comment in Kotlin is a lexical construct ignored by the compiler during the lexical analysis phase. It is initiated by the double forward-slash token (//).

The scope of a single-line comment begins immediately following the // characters and extends to the end of the current line, terminating automatically upon encountering a line break character (e.g., \n or \r\n). Any text, symbols, or valid Kotlin syntax placed within this scope is treated as plain text and is not evaluated or executed.

Syntax Visualization

// This comment occupies an entire line. The compiler ignores this text.
val immutableVariable = 10 

val stringVariable = "Kotlin" // This is a trailing inline comment.

Single-line comments are strictly bound to the line on which they are declared. They cannot span multiple lines without reiterating the // token at the beginning of each subsequent line. Syntactically, they can be placed at the absolute start of a line, preceded by arbitrary whitespace, or appended directly after a valid Kotlin statement or expression.

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