# Apostrophe Comments
A comment is marked by an apostrophe (
'), and ignored when the code executes. Comments help explain your code to future readers, including yourself.
Since all lines starting with a comment are ignored, they can also be used to prevent code from executing (while you debug or refactor). Placing an apostrophe
' before your code turns it into a comment. (This is called commenting out the line.)
Sub InlineDocumentation() 'Comments start with an "'" 'They can be place before a line of code, which prevents the line from executing 'Debug.Print "Hello World" 'They can also be placed after a statement 'The statement still executes, until the compiler arrives at the comment Debug.Print "Hello World" 'Prints a welcome message 'Comments can have 0 indention.... '... or as much as needed '''' Comments can contain multiple apostrophes '''' 'Comments can span lines (using line continuations) _ but this can make for hard to read code 'If you need to have mult-line comments, it is often easier to 'use an apostrophe on each line 'The continued statement syntax (:) is treated as part of the comment, so 'it is not possible to place an executable statement after a comment 'This won't run : Debug.Print "Hello World" End Sub 'Comments can appear inside or outside a procedure
# REM Comments
Sub RemComments() Rem Comments start with "Rem" (VBA will change any alternate casing to "Rem") Rem is an abbreviation of Remark, and similar to DOS syntax Rem Is a legacy approach to adding comments, and apostrophes should be preferred Rem Comments CANNOT appear after a statement, use the apostrophe syntax instead Rem Unless they are preceded by the instruction separator token Debug.Print "Hello World": Rem prints a welcome message Debug.Print "Hello World" 'Prints a welcome message 'Rem cannot be immediately followed by the following characters "!,@,#,$,%,&" 'Whereas the apostrophe syntax can be followed by any printable character. End Sub Rem Comments can appear inside or outside a procedure
If you need to comment or uncomment several lines at once, you can use the IDE's Edit Toolbar buttons:
Comment Block - Adds a single apostrophe to the start of all selected lines
Uncomment Block - Removes the first apostrophe from the start of all selected lines
Multi-line Comments Many other languages support multi-line block comments, but VBA only allows single-line comments.