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Variable Types

Variables can store different kinds of data. Altoura supports 4 variable types, each designed for a specific purpose.

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The 4 Variable Types

String

Text values (words, sentences, single letters)

Number

Numeric values (integers and decimals)

Boolean

True or false only

Array

A list of values (ordered collection)
Variable editor showing Type dropdown set to Number with Default Value, Allowed Values, and Min/Max fields

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String

What it is: Text values — words, sentences, single characters, or any string of characters. Default value: Usually "" (empty string) Examples:
  • "correct" (single word)
  • "John Smith" (multiple words)
  • "Safety-Procedure-001" (identifier with special characters)
  • "The valve is open." (sentence)
  • "" (empty)
When to use:
  • Store the learner’s name, username, or email
  • Store selected answers (“Option A”, “Door B”)
  • Store status values (“open”, “closed”, “waiting”)
  • Store IDs or codes
Example variable: 
Variable Name: selectedAnswer
Type: string
Default Value: ""
// Stores the choice the learner made in a quiz

Later in actions:
- If learner picks "Option A", Set Variable: selectedAnswer = "Option A"
- In condition: selectedAnswer == "Option A" ? go to "Correct Path" : "Incorrect Path"
Using strings in conditions: 
selectedAnswer == "correct"
userName === "admin"
feedbackText !== ""

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Number

What it is: Numeric values — integers (whole numbers) or decimals (numbers with a point). Default value: Usually 0 Examples:
  • 0, 1, 100 (integers)
  • 3.14, 0.5, 99.99 (decimals)
  • -10 (negative)
When to use:
  • Store scores or points
  • Store attempt counts
  • Store time values (in seconds or milliseconds)
  • Store percentages or ratings
  • Store object positions or angles
Example variables: 
Variable Name: score
Type: number
Default Value: 0
// Running total of points

Variable Name: attempts
Type: number
Default Value: 0
// How many times learner has tried

Variable Name: elapsedSeconds
Type: number
Default Value: 0
// Time spent in training

Later in actions:
- Set Variable: score = score + 10 (add points)
- Set Variable: attempts = attempts + 1 (increment)
- Set Variable: elapsedSeconds = (now() - startTime) / 1000 (calculate)
Using numbers in conditions: 
score >= 80
attempts < 3
elapsedSeconds > 120

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Boolean

What it is: A value that is either true or false — nothing else. Default value: Usually false or true Examples:
  • true (yes, complete, open, on)
  • false (no, incomplete, closed, off)
When to use:
  • Track yes/no states (is something complete? is it open?)
  • Track toggles (is audio enabled? is advanced mode on?)
  • Gate features (has learner watched the intro?)
  • Status flags (is this section unlocked?)
Example variables: 
Variable Name: isQuizComplete
Type: boolean
Default Value: false
// Quiz not started yet

Variable Name: hasWatchedIntro
Type: boolean
Default Value: false
// Intro not watched yet

Variable Name: audioEnabled
Type: boolean
Default Value: true
// Audio on by default

Later in actions:
- Set Variable: isQuizComplete = true (when quiz finishes)
- Set Variable: hasWatchedIntro = true (after intro plays)
Using booleans in conditions: 
isQuizComplete == true
hasWatchedIntro == false
audioEnabled ? "Play sound" : "Silent"
Booleans are simple and fast. Use them for simple on/off states instead of strings like “complete”/“incomplete”.

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Array

What it is: An ordered list of values. Each item in the list is accessed by its position (1st item, 2nd item, etc.). Default value: Usually [] (empty array) or an initial list like ["step1", "step2"] Examples: 
// List of completed steps
["Read instructions", "Identify valve", "Turn valve"]

// List of answers
["Option A", "Option B", "Option A"]

// List of numbers (scores from multiple attempts)
[85, 92, 78]

// Empty array
[]
When to use:
  • Store a list of items (completed steps, selected choices)
  • Store a history (previous scores, timestamps)
  • Track multiple related values in order
Example variable: 
Variable Name: completedSteps
Type: array
Default Value: []

Later in actions:
- Append to array: completedSteps = ["Read intro", "Start task", "Review results"]

In conditions: len(completedSteps) >= 3 ? "All steps done" : "In progress"

In text: "You've completed {{len(completedSteps)}} of 5 steps."
Using arrays in conditions: 
len(completedSteps) >= 3          // At least 3 items
len(selectedAnswers) == 10        // Exactly 10 answers
len(completedSteps) > 0           // Array is not empty

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Choosing the Right Type: Quick Reference

Use this table to decide which type to use:
DataTypeWhy
A learner’s name, usernamestringText value
Score, points, countnumberNumeric value
Answer to a multiple-choice questionstringText value (“Option A”)
Is something complete? Open?booleanYes/no only
Number of attemptsnumberNumeric value
Elapsed time (seconds)numberNumeric value
List of visited statesarrayOrdered list of items
Quiz answers for 5 questionsarrayList of answers
Multiple scores from retriesarrayList of numbers
A flag (audio enabled, intro watched)booleanYes/no only

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Type Compatibility and Conversion

Be careful when mixing types: 
// ✓ OK: Compare same types
score == 80              // number == number
selectedAnswer == "A"    // string == string
isComplete == true       // boolean == boolean

// ⚠ Risky: Different types may behave unexpectedly
score == "80"            // Might work, but not recommended
"80" + 20 = ?            // String concatenation or math? Unclear

// ✓ OK: Use functions to convert
len(arrayVariable)       // Works on arrays and strings
clamp(score, 0, 100)     // Works on numbers
When building conditions, make sure you’re comparing the right types. A string “80” is different from a number 80. If you’re comparing numbers, make sure both are numbers.

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Default Values Matter

Every variable must have a default value. Choose defaults carefully:
VariableTypeDefaultWhy
scorenumber0No points yet
selectedAnswerstring""No answer selected
isCompletebooleanfalseNot done
completedStepsarray[]No steps completed
Defaults are important because your conditions rely on them. If a variable starts undefined or null, some conditions might fail.

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Best Practices

Changing types later can break conditions and actions. Plan ahead.
Strings, numbers, and booleans are easier to work with than arrays. Use them unless you really need a list.
Instead of answer1, answer2, answer3, use one selectedAnswers array.
Empty strings, zero, false, [] — use sensible defaults so conditions work correctly.

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Next Steps

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