Expressions

Expressions let you write dynamic logic — calculations, comparisons, and string manipulation.

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What Are Expressions?

Expressions are mini-formulas that compute values:

var.balance + 100          → adds 100 to balance
user.first_name + " Smith" → combines strings
var.age >= 18              → checks if adult

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Where to Use Expressions

Expressions work in:

Place	Example
Condition nodes	var.balance > 0
Transform nodes	value * 2
Text templates	{{var.balance + 10}}
Validation	value >= 18 && value <= 100

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Basic Math

Operation	Symbol	Example	Result
Add	+	5 + 3	8
Subtract	-	10 - 4	6
Multiply	*	6 * 7	42
Divide	/	20 / 4	5
Remainder	%	17 % 5	2

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Comparisons

Comparison	Symbol	Example	Result
Equals	==	5 == 5	true
Not equals	!=	5 != 3	true
Greater than	>	10 > 5	true
Less than	<	3 < 5	true
Greater or equal	>=	5 >= 5	true
Less or equal	<=	4 <= 5	true

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Logic (And/Or/Not)

Operation	Symbol	Example	Result
And	&&	true && false	false
Or	||	true || false	true
Not	!	!true	false

Combining Conditions

var.age >= 18 && var.is_verified

Both must be true.

var.role == "admin" || var.role == "moderator"

Either can be true.

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Working with Text

Combining Strings

"Hello, " + user.first_name + "!"
→ "Hello, Alice!"

Useful Functions

Function	What It Does	Example
len(x)	Length	len("hello") → 5
upper(x)	Uppercase	upper("hello") → "HELLO"
lower(x)	Lowercase	lower("HELLO") → "hello"
trim(x)	Remove whitespace	trim(" hi ") → "hi"
contains(x, y)	Has substring?	contains("hello", "ell") → true

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Working with Numbers

Function	What It Does	Example
int(x)	Convert to integer	int("42") → 42
float(x)	Convert to decimal	float("3.14") → 3.14
abs(x)	Absolute value	abs(-5) → 5
min(a, b)	Smaller value	min(5, 3) → 3
max(a, b)	Larger value	max(5, 3) → 5

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Working with Lists

Function	What It Does	Example
len(arr)	Count items	len([1,2,3]) → 3
first(arr)	First item	first([1,2,3]) → 1
last(arr)	Last item	last([1,2,3]) → 3
join(arr, sep)	Combine to string	join(["a","b"], "-") → "a-b"

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The Ternary Operator

A quick if/else in one line:

condition ? value_if_true : value_if_false

Examples:

var.age >= 18 ? "Adult" : "Minor"

var.balance > 0 ? var.balance : 0

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Template Expressions

Inside text, use {{...}}:

Hello {{user.first_name}}!
Your balance: ${{var.balance}}
Status: {{var.is_active ? "Active" : "Inactive"}}

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Common Patterns

Calculate Discount

var.total * (1 - var.discount_rate)

Format Currency

"$" + string(var.balance)

Check Empty

var.email != "" && var.email != nil

Safe Division

var.count > 0 ? var.total / var.count : 0

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Tips

Start Simple

Get basic expressions working first, then add complexity.

Test Your Logic

Use a Send Message node to show expression results during development:

Debug: {{var.age >= 18}}

Type Matters

"5" (text) is different from 5 (number). Use int() or float() to convert.

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Quick Reference

Common Checks

Purpose	Expression
Is registered?	var.registered == true
Has balance?	var.balance > 0
Is admin?	user.id == 12345
Text not empty?	len(var.name) > 0
Contains word?	contains(input, "help")

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Next Steps

• Variables → — Store expression results
• Logic Nodes → — Use expressions in conditions