SET

Assign values to variables in BASIC dialogs.

Syntax

SET variable = value

or simply:

variable = value

Parameters

Description

The SET keyword assigns values to variables within BASIC dialog scripts. Variables are dynamically typed and can hold any type of value. The SET keyword is optional - you can use direct assignment with =.

Variables are scoped to the current dialog execution and persist throughout the conversation session until explicitly changed or the session ends.

Examples

Basic Assignment

SET name = "John Doe"
SET age = 25
SET is_premium = true
SET score = 98.5

Direct Assignment (without SET)

name = "Jane Smith"
count = 0
message = "Welcome!"

Array Assignment

SET colors = ["red", "green", "blue"]
SET numbers = [1, 2, 3, 4, 5]
SET mixed = ["text", 123, true]

Object/Map Assignment

SET user = {
    "name": "Alice",
    "email": "alice@example.com",
    "age": 30,
    "active": true
}

Dynamic Values

SET current_time = NOW()
SET user_input = HEAR "What's your name?"
SET calculated = price * quantity * tax_rate
SET formatted = FORMAT("Hello, {0}!", username)

Variable Types

BASIC supports these variable types:

• String: Text values
• Number: Integers and decimals
• Boolean: true/false
• Array: Ordered lists
• Object: Key-value maps
• Null: Empty/undefined

Variable Naming

Valid variable names:

• Start with letter or underscore
• Contain letters, numbers, underscores
• Case-sensitive
• No reserved keywords

Examples:

SET userName = "John"
SET user_name = "John"
SET _private = true
SET value123 = 456
SET firstName = "Jane"

Invalid names:

' These will cause errors
SET 123name = "error"      ' Starts with number
SET user-name = "error"    ' Contains hyphen
SET if = "error"           ' Reserved keyword

Variable Scope

Session Variables

Regular variables exist for the session:

SET session_data = "persists during conversation"

Global Variables

Use special prefixes for broader scope:

SET $global_var = "accessible across dialogs"
SET @bot_var = "bot-level variable"

Temporary Variables

SET _temp = "temporary use"
' Prefix with underscore for temporary/internal use

Type Conversion

Variables automatically convert types when needed:

SET text = "123"
SET number = text + 0       ' Converts to number: 123
SET back_to_text = number + ""  ' Converts to string: "123"
SET boolean = number > 100  ' Converts to boolean: true

Operations on Variables

String Operations

SET full_name = first_name + " " + last_name
SET uppercase = UPPER(name)
SET length = LEN(message)
SET substring = MID(text, 1, 5)

Numeric Operations

SET sum = a + b
SET difference = a - b
SET product = a * b
SET quotient = a / b
SET remainder = a MOD b
SET power = a ^ b

Array Operations

SET first = colors[0]
SET last = colors[LEN(colors) - 1]
colors[1] = "yellow"  ' Modify array element
SET combined = array1 + array2  ' Concatenate

Object/Map Operations

SET email = user["email"]
SET age = user.age
user["status"] = "active"
user.last_login = NOW()

Conditional Assignment

SET status = IF(score >= 70, "pass", "fail")
SET discount = IF(is_member, 0.2, 0.1)
SET greeting = IF(hour < 12, "Good morning", "Good afternoon")

Common Patterns

Counter Variables

SET counter = 0
FOR i = 1 TO 10
    counter = counter + 1
NEXT

Flag Variables

SET is_complete = false
' ... process ...
SET is_complete = true

Accumulator Variables

SET total = 0
FOR EACH item IN cart
    total = total + item.price
NEXT

State Variables

SET state = "initial"
' ... logic ...
SET state = "processing"
' ... more logic ...
SET state = "complete"

Best Practices

1. Use descriptive names: customer_email instead of e
2. Initialize variables: Set initial values before use
3. Use consistent naming: camelCase or snake_case
4. Avoid global pollution: Use local variables when possible
5. Clean up large variables: Set to null when done
6. Document complex variables: Add comments
7. Validate before use: Check if variable exists

Error Handling

' Check if variable exists
IF EXISTS(user_data) THEN
    SET name = user_data.name
ELSE
    SET name = "Guest"
END IF

' Safe assignment with default
SET value = GET_VALUE_OR_DEFAULT(config.setting, "default")

Memory Management

' Clear large variables when done
SET big_data = LOAD_FILE("large.json")
' ... use big_data ...
SET big_data = null  ' Free memory

Related Keywords

• GET - Retrieve data from external sources
• HEAR - Get user input into variable
• FORMAT - Format values for assignment
• SET BOT MEMORY - Persistent storage

Implementation Notes

Variables are stored in the BASIC engine’s scope map and persist for the duration of the dialog execution. The SET keyword is syntactic sugar - the parser treats both SET x = y and x = y identically.