CFML Syntax — Tags and Script

Tag syntax (classic)

CFML started as an HTML-like templating language. Every built-in operation is also available as an HTML-style tag.

<cfset name = "World">
<cfoutput>Hello, #name#!</cfoutput>

Tags are case-insensitive and must be paired (or self-closed). The hash signs #name# signal variable interpolation inside a <cfoutput> block.

Anatomy of a CFML tag: opening tag, optional attributes, hash-delimited interpolation, and closing tag.

Activity: In your lab, click the Terminal tab. Create syntax_tag.cfm in the ColdFusion web root using sudo tee:

sudo tee /opt/coldfusion2025/cfusion/wwwroot/syntax_tag.cfm << 'EOF'
<cfset message = "I am using tag syntax">
<cfoutput>#message# — tag</cfoutput>
EOF

To see the rendered page in the browser:

1. Click the ColdFusion 2025 tab in your lab — it shows the CF Admin login page inside the lab frame.
2. Right-click that tab button and choose "Open Link in New Tab" — this opens the engine's root URL in a real browser window with a full address bar.
3. In the address bar, replace whatever path is shown with /syntax_tag.cfm and press Enter.

https://<your-session-id>.iximiuz.com/syntax_tag.cfm

You can also verify from the Terminal without opening a browser at all:

curl -s http://localhost:8500/syntax_tag.cfm
# Expected output: I am using tag syntax — tag

Script syntax (modern)

Since ColdFusion 9, the full language is available in ECMAScript-style syntax inside a <cfscript> block. Modern CF codebases tend to use script exclusively.

<cfscript>
  name = "World";
  writeOutput("Hello, #name#!");
</cfscript>

Both syntaxes compile to the same bytecode. You can mix them freely — a common pattern is to keep business logic in <cfscript> and HTML structure in tags.

Both syntaxes are compiled by the same CFML engine to identical JVM bytecode.

Activity: Still in the Terminal, create syntax_script.cfm:

sudo tee /opt/coldfusion2025/cfusion/wwwroot/syntax_script.cfm << 'EOF'
<cfscript>
  writeOutput("I am using cfscript — script syntax");
</cfscript>
EOF

In the browser window you opened earlier, change the path to /syntax_script.cfm and reload. Or from the Terminal:

curl -s http://localhost:8500/syntax_script.cfm
# Expected output: I am using cfscript — script syntax

When to use each

What does production look like today?

In modern CFML codebases (2020 onward), cfscript dominates. Here's why:

• Frameworks are script-first. ColdBox, the most widely adopted CFML MVC framework, writes everything in cfscript. If you work on any ColdBox application — which covers a large share of active CF projects — you write script exclusively.
• Tooling favours script. Code formatters (CFFormat), linters (CFLint), and IDE plugins all have better support for script syntax. Tag-heavy files produce more false positives and formatting noise.
• Readability at scale. In a large CFC with 20+ functions, tag syntax adds significant visual noise. Script reads closer to Java or JavaScript, which most CF developers already know.
• The one exception: <cfquery>. Even in fully script-based codebases, many teams keep SQL in <cfquery> tags because the SQL sits naturally inside the tag body without string concatenation. queryExecute() is the script alternative, but <cfquery> is still widely accepted and idiomatic.

Conditionals

CFML conditionals work in both syntaxes. The cfscript form mirrors JavaScript; the tag form uses attribute-style operators like GTE, LTE, EQ, NEQ.

<cfscript>
  score = 85;
  if (score >= 90) {
    writeOutput("A");
  } else if (score >= 80) {
    writeOutput("B");
  } else {
    writeOutput("C");
  }
</cfscript>

Tag equivalent:

<cfset score = 85>
<cfif score GTE 90>
  A
<cfelseif score GTE 80>
  B
<cfelse>
  C
</cfif>

Quick reference: CFML tag syntax (left) vs. cfscript syntax (right) for conditionals and loops.

Activity: Update syntax_script.cfm to add a conditional. In the Terminal, overwrite the file:

sudo tee /opt/coldfusion2025/cfusion/wwwroot/syntax_script.cfm << 'EOF'
<cfscript>
  writeOutput("I am using cfscript — script syntax");
  score = 85;
  if (score >= 90) {
    writeOutput(" — Grade: A");
  } else if (score >= 80) {
    writeOutput(" — Grade: B");
  } else {
    writeOutput(" — Grade: C");
  }
</cfscript>
EOF

Reload /syntax_script.cfm in the browser window to see the grade appended to the output. Or from the Terminal:

curl -s http://localhost:8500/syntax_script.cfm
# Expected: I am using cfscript — script syntax — Grade: B

Loops

ColdFusion supports for, while, and for...in in cfscript, and <cfloop> in tag syntax. The most common is the index loop:

<cfscript>
  for (i = 1; i <= 5; i++) {
    writeOutput("Item #i#<br>");
  }
</cfscript>

Tag equivalent:

<cfloop index="i" from="1" to="5">
  Item #i#<br>
</cfloop>

ColdFusion also supports iterating over arrays and structs:

<cfscript>
  fruits = ["apple", "banana", "cherry"];
  for (fruit in fruits) {
    writeOutput("#fruit#<br>");
  }
</cfscript>

Activity: In the Terminal, create syntax_loop.cfm:

sudo tee /opt/coldfusion2025/cfusion/wwwroot/syntax_loop.cfm << 'EOF'
<cfscript>
  for (i = 1; i <= 5; i++) {
    writeOutput(i & "<br>");
  }
</cfscript>
EOF

Change the path to /syntax_loop.cfm in the browser window — the <br> tags render properly so the numbers appear on separate lines. Or from the Terminal:

curl -s http://localhost:8500/syntax_loop.cfm
# Expected: 1<br>2<br>3<br>4<br>5<br>

All loop forms — putting it together

CFML has four loop constructs you will encounter in real codebases. This exercise writes them all into a single file so you can see how they look side by side.

Activity: In the Terminal, create syntax_loop_all.cfm:

sudo tee /opt/coldfusion2025/cfusion/wwwroot/syntax_loop_all.cfm << 'EOF'
<cfscript>
  // 1. Index loop — numeric counter
  writeOutput("<strong>Index loop:</strong><br>");
  for (i = 1; i <= 3; i++) {
    writeOutput("  step #i#<br>");
  }

  // 2. For-in loop — array
  writeOutput("<br><strong>Array loop:</strong><br>");
  languages = ["CFML", "Java", "JavaScript"];
  for (lang in languages) {
    writeOutput("  #lang#<br>");
  }

  // 3. For-in loop — struct
  writeOutput("<br><strong>Struct loop:</strong><br>");
  info = {engine: "ColdFusion", version: "2025", port: "8500"};
  for (key in info) {
    writeOutput("  #key# = #info[key]#<br>");
  }

  // 4. While loop
  writeOutput("<br><strong>While loop:</strong><br>");
  count = 1;
  while (count <= 3) {
    writeOutput("  count is #count#<br>");
    count++;
  }
</cfscript>
EOF

Change the path to /syntax_loop_all.cfm in your browser window to see all four loop types rendered. Or from the Terminal:

curl -s http://localhost:8500/syntax_loop_all.cfm

The browser renders all four loop forms — this is what you should see at /syntax_loop_all.cfm.

Need to fix a file? Edit it with vi

If a file has a typo or you want to tweak it without rewriting the whole thing, vi (or vim) is available in the lab Terminal.

Open the file:

vi /opt/coldfusion2025/cfusion/wwwroot/syntax_loop_all.cfm

Copy to clipboard

Basic vi commands:

Key	What it does
i	Enter insert mode — you can now type and edit
Esc	Leave insert mode, go back to normal mode
dd	Delete the current line (normal mode)
u	Undo the last change (normal mode)
:w + Enter	Save the file (normal mode)
:q + Enter	Quit vi (normal mode, only if no unsaved changes)
:wq + Enter	Save and quit in one step
:q! + Enter	Quit without saving (discard changes)

Quickest edit workflow:

1. vi filename.cfm — open the file
2. Navigate to the line you want to change (arrow keys work)
3. Press i to enter insert mode
4. Make your edit
5. Press Esc to return to normal mode
6. Type :wq and press Enter to save and exit

vi open with syntax_loop_all.cfm — press i to start editing, Esc then :wq to save and exit.

React / Vue / Angular        ColdFusion 2025
─────────────────────        ───────────────────────
fetch("/api/tickets")  →     tickets.cfm queries DB
                       ←     returns JSON array
renders ticket list          done — CF is invisible

When all the checks above are green, this lesson is complete. Your progress is saved automatically — move straight on to the next lesson.