为何Visual Basic选用单引号作为注释符？该选择是否有特定原因？

Great question! It’s totally valid to wonder why VB opted for such a common character like the single quote (') for comments instead of a more distinct sequence. Let’s dive into the historical and design reasons behind this choice:

• Legacy BASIC Compatibility
  Visual Basic evolved directly from earlier BASIC dialects (like GW-BASIC, QuickBASIC) that already used single quotes for inline comments. Microsoft kept this convention to make the transition smooth for existing BASIC developers—no need to re-learn a new comment syntax when moving to VB. For example, this classic BASIC snippet would feel familiar to VB users right away:

  PRINT "Hello World" ' Display greeting to user
  

• Alignment with BASIC’s "Beginner-Friendly" Philosophy
  BASIC was designed to be accessible to new programmers, and the single quote fits that perfectly. It’s a single, easy-to-type character (no shift combinations required, unlike // or /*), which lowers the barrier for beginners writing their first lines of code. The goal was to keep syntax as simple and intuitive as possible, and a one-character comment marker delivers on that.

• Avoiding Syntax Conflicts
  VB uses double quotes ("") to wrap string literals, so a single quote never clashes with string definitions. For example, a string like Dim userMessage As String = "Don't forget to save!" works seamlessly—the compiler knows the single quote inside the double quotes is part of the string, not the start of a comment. If VB had chosen a different character (like #, which is used for date literals #12/31/2024#), it would have created unnecessary syntax conflicts.

• Practicality in Early Development Environments
  Back when VB was first released, keyboard layouts and text editors were less sophisticated than today. The single quote was a universally accessible character across almost all keyboard setups, making it a reliable choice. More obscure characters might have been harder to type or caused issues in older terminal/editor environments.

To address your point about readability—you’re right that single quotes can blend into dense code at first glance. However, VB has always supported the REM keyword as an alternative comment marker (e.g., REM This is a comment too), and modern IDEs like Visual Studio automatically highlight comments in a distinct color, making them easy to spot even with the single quote syntax.

内容的提问来源于stack exchange，提问作者dreing1130