Backslash Escape + #if Conditional Syntax
1. Backslash \ Escape Rules
Pre‑defined variable：#set($dog = "woof woof")
| VTL Code | Rendered Output | Explanation |
|---|---|---|
$dog | woof woof | Normal variable resolution |
\$dog | $dog | Single backslash: escapes the following $, disables variable parsing and prints $ literally |
\\$dog | \woof woof | First \ escapes second \ → outputs \;remaining $dog resolves normally |
\\\$dog | \$dog | \\ outputs \, \$ outputs $ |
\\\\$dog | \woof woof | \\ outputs \, \\ outputs \;$dog resolves variable |
- Velocity variable names must start with a letter，
$10.0will not be treated as variable and outputs as‑is；so writingMicrosoft $10.0 USDin text requires no extra escaping； - Consecutive backslashes cancel out in pairs；only the
\$combination can escape dollar‑sign； - To display
$variableNameliterally on page, standard syntax：\$dog.
2. #if Branch Conditional Syntax
#set($ages = 22)
#if ($ages <13)
<h1>You are a child</h1>
#elseif ($ages <18)
<h1>You are a teenager</h1>
#elseif ($ages <35)
<h1>You are a young adult</h1>
#elseif ($ages <60)
<h1>You are middle‑aged</h1>
#else
<h1>You are elderly</h1>
#endCode language: PHP (php)Execution Result
$ages=22, satisfies 22 < 35 → output：<h1>You are a young adult</h1>
Notes
- You must close block with
#end, missing it will trigger parsing error； - Keyword：
#elseif（do NOT write as #else if, that is invalid syntax）； - Supported operators：
< > <= >= == != && ||and more； - Matching rule: evaluate conditions top‑down. Once one branch matches, subsequent branches are skipped.
Escape characters and #if conditionals
Previous: Extension methods