> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wizflow.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Variables
> Create dynamic values from chatflow responses, trigger outputs, and data models
Variables enable dynamic computation and data transformation, acting like spreadsheet formulas that calculate values in real-time based on user responses and other data sources. Transform, calculate, and derive new values from existing data without requiring server-side processing.
## How Variables Work
Variables update instantly as users provide responses, enabling dynamic content and calculations throughout your chatflow.
Create readable names for data sources, then write JavaScript expressions using these aliases to perform calculations.
Variables can reference other variables, enabling complex multi-step calculations and data transformations.
All calculations are visible and auditable through JavaScript expressions, ensuring complete transparency.
## Common Use Cases
**Financial Formulas & Computations**
* Basic arithmetic: `income * 12` for annual salary
* Advanced math: `Math.pow()`, `Math.sqrt()`, `Math.round()`
* Financial calculations: loan payments, compound interest, ROI
* Statistical operations: averages, percentages, ratios
```javascript theme={null}
// Calculate BMI
weight / (height * height)
// Monthly loan payment calculation
principal * (rate * Math.pow(1 + rate, months)) / (Math.pow(1 + rate, months) - 1)
```
**String Manipulation & Formatting**
* Extract first/last names: `userFullName.split(' ')[0]`
* Case conversion: `.toUpperCase()`, `.toLowerCase()`
* Text parsing: split strings, extract substrings
* Data concatenation: combine multiple fields
```javascript theme={null}
// Extract first name for personalization
userFullName.split(' ')[0]
// Format phone number display
`(${phone.slice(0,3)}) ${phone.slice(3,6)}-${phone.slice(6)}`
```
**Smart Decision Making**
* Ternary operators: `age >= 18 ? "adult" : "minor"`
* Multi-condition evaluations for business rules
* Risk scoring based on multiple criteria
* Data validation with fallbacks
```javascript theme={null}
// Age-based eligibility
age >= 18 ? "eligible" : "requires_guardian"
// Risk assessment scoring
(creditScore > 700 ? 50 : 0) + (income > 50000 ? 30 : 0) + (hasAssets ? 20 : 0)
```
**Complex Data Manipulation**
* Array operations: process lists and extract elements
* Object manipulation: access nested properties
* Type conversions: safely convert between data types
* Data cleaning: remove unwanted characters, normalize formats
```javascript theme={null}
// Calculate total from array of values
expensesList.reduce((sum, expense) => sum + expense.amount, 0)
// Clean and format currency
Math.round(parseFloat(userInput.replace(/[^0-9.-]/g, '')) * 100) / 100
```
## Variable Editor
### Expression System
Variables use **aliases** connected to **JavaScript expressions**:
Define readable names for your data sources:
* `userAge` instead of complex resource references
* `monthlyIncome` for salary responses
* `creditScore` from external API calls
Use JavaScript with your aliases to create calculations:
```javascript theme={null}
// Simple calculation
userAge >= 65 ? pensionAmount * 1.2 : pensionAmount
// Complex financial formula
Math.min(monthlyIncome * 0.28, (monthlyIncome * 0.36) - monthlyDebt)
```
Use the expression tester with mock values to ensure your logic works correctly before deployment.
Use your variables throughout the chatflow in messages, conditions, and other variables.
### Editor Features
* **Ctrl+Space** triggers intelligent suggestions
* Auto-detects available response fields
* Suggests variable names and functions
* Context-aware completions
* Visual mapping of aliases to data sources
* Automatic detection of undefined aliases
* Smart suggestions for missing connections
* Resource browser integration
* Test expressions with mock values
* Validate complex calculations
* Debug multi-step logic
* Preview results before deployment
* Built-in null checking capabilities
* Default value support
* Type validation assistance
* Runtime error prevention
## Where to Use Variables
Variables integrate seamlessly throughout your chatflow:
**Personalized Communication**
Display calculated values in messages using dynamic content. Perfect for showing personalized results, progress indicators, or calculated recommendations.
*Example: "Based on your income of \$X, your recommended savings rate is Y%"*
**Smart Branching**
Use calculated values in conditions to create intelligent flow paths. Enable complex eligibility checks, risk-based routing, and personalized user journeys.
*Example: Route users to different application processes based on calculated risk scores*
**External System Integration**
Pass calculated values to triggers for external processing, API calls, or data storage. Enable complex data transformation before sending to external systems.
*Example: Send calculated financial metrics to CRM or generate personalized PDF reports*
**Complex Multi-Step Calculations**
Reference other variables to build sophisticated calculation chains. Break complex formulas into manageable, reusable components.
*Example: Base loan eligibility → Credit risk score → Final approval decision*
## Real-World Examples
### Financial Services
```javascript Loan Eligibility theme={null}
// Calculate maximum loan amount
Math.min(
monthlyIncome * 0.28 * 12 * loanTermYears,
(monthlyIncome * 0.36 - monthlyDebt) * 12 * loanTermYears
)
```
```javascript Risk Assessment theme={null}
// Multi-factor risk scoring
(creditScore >= 750 ? 40 : creditScore >= 650 ? 25 : 10) +
(debtToIncomeRatio <= 0.3 ? 30 : debtToIncomeRatio <= 0.4 ? 15 : 5) +
(yearsAtJob >= 2 ? 20 : 10) +
(hasAssets ? 10 : 0)
```
```javascript Pension Calculation theme={null}
// Annual pension projection
currentAge <= 65 ?
savingsAmount * Math.pow(1 + returnRate, 65 - currentAge) :
savingsAmount * withdrawalRate
```
### Health & Insurance
```javascript BMI Calculation theme={null}
// Body Mass Index with classification
weight / Math.pow(height / 100, 2)
```
```javascript Insurance Premium theme={null}
// Age-based premium calculation
basePremium * (age < 30 ? 0.8 : age < 50 ? 1.0 : age < 65 ? 1.3 : 1.6) *
(smoker ? 1.5 : 1.0) * (hasConditions ? 1.2 : 1.0)
```
## Best Practices
**Use Clear Variable Names**
Choose names that explain the variable's purpose:
* `monthlyMortgagePayment` not `payment`
* `userAgeInYears` not `age`
* `totalAnnualIncome` not `income`
**Handle Edge Cases**
Include validation and default values:
```javascript theme={null}
// Safe division with fallback
income > 0 ? expenses / income : 0
// Null checking
userName ? userName.trim() : "Guest"
```
**Break Down Complex Logic**
Create smaller, reusable variables:
* `grossMonthlyIncome` → `netMonthlyIncome` → `loanEligibility`
* Build calculation chains step by step
* Make debugging easier
**Document Complex Formulas**
Use descriptive variable names and comments:
* Explain business rules and assumptions
* Document data sources and calculations
* Include examples of expected inputs/outputs
## Performance & Reliability
**Real-time Calculation**
Variables are calculated instantly as users progress through your chatflow:
* **Lightweight Processing** - Client-side JavaScript execution
* **No Server Delays** - Calculations happen in the user's browser
* **Dynamic Updates** - Values refresh automatically as inputs change
* **Reliable Performance** - No external dependencies for basic calculations
**Calculation Limitations**
Variables support standard JavaScript with some restrictions:
* **Synchronous only** - No async operations or API calls
* **No function declarations** - Use expressions and built-in functions
* **Client-side only** - Complex server-side calculations should use triggers
* **Memory limits** - Very large datasets should be processed server-side
***
## Related Features
Use variables in branching logic to create dynamic flow paths
Pass calculated values to external systems and automations
Understanding the data sources available for variable calculations
Advanced financial calculation capabilities and triggers