Example

This example function calculates issue priority based on severity and environment. It uses conditional logic to demonstrate parameter passing.

function

calculatePriority("Critical", "Production");  // Returns "Highest"

Description:

The function calculatePriority("Critical", "Production") receives "Critical" and "Production" as inputs and checks the first condition against an actual Jira issue. If the condition is met, it changes the priority of the Jira issue to Highest. If the condition is not met, the function continues by checking the next condition and so on.

This function can be reused throughout your SIL program whenever you need to calculate priority based on severity and environment. For example, when issues are created, when severity or environment fields are updated, as part of validation rules, or in bulk update operations.

Functions definition

SIL has strict rules about where function definitions can appear in your code.

The correct order must be:

1. Global variable declarations (with initialization if needed), including here any constant declarations

2. Function definitions

3. Executable code

This rule helps ensure that all functions are available when needed and prevents potential issues with code organization and variable scoping.

Invalid definition example

// This is INVALID:
number i;                 // Variable declaration
const number pi = 3.14;   // Constant declaration
i = 0;

The error occurs because you can't have executable code (like i = 0; where i is initialized to a constant) before function definitions. 

Valid definition example

// This is VALID:
number i = 0;            //

 Functions must be defined after declarations but before executable code
function circleArea(number r) {
    return (i + r) * (i + r) * pi;
}

// Executable code comes after all function definitions
number r = 10;
runnerLog("Area of radius " + r + " is " + circleArea(r));       //returns Area of radius 10 is 314
i++;
runnerLog("Area of radius " + (r + i) + " is " + circleArea(r));  // returns Area of radius 11 is 379.94

Running the above code in

SIL Manager returns the following (in the Editor console):

Image Added

Parameters definition

Here’s what you need to know about parameters definition in a function:

• Parameters can be of any valid SIL type (string, number, boolean, etc.)

• Parameters are passed by value; changes inside the function don't affect the original variables.

• The parameter list can be of any length; it can be empty.

Examples

This example illustrates how different parameter types are defined and used in a function.

// Function with no parameters
function zero() {
    return 0;
}

// Function showing different parameter types
function 

isActive,      // Boolean parameter
    string[] comments      // Array of strings
) {
    // Using the parameters
    runnerLog("Processing data for: " + name);
    runnerLog("Age: " + age);
    runnerLog("First score: " + scores[0]);
    runnerLog("Status: " + isActive);
    runnerLog("First comment: " + comments[0]);
}

// Example usage:
string studentName = "John";
number studentAge = 20;
number[] testScores = {95, 87, 92};
boolean active = true;
string[] feedback = {"Good work", "Needs improvement"};

processData(studentName, studentAge, testScores, active, feedback);

Running the example usage code in the SIL Manager returns the following result:

Pass-by-value behavior

Parameters in UDFs are passed by value in the following way:

• A copy of the value is passed to the function.

• Changes to the parameter inside the function don't affect the original variable.

• The original variable keeps its value after the function exits.

• Pass-by-value behavior is the same for all SIL basic types, arrays, and structs.

Example

This example demonstrates pass-by-value behavior for a UDF that takes a number parameter and adds 10 to it.

function updateScore(number score) {
    // Because of pass-by-value, 'score' is a local copy
    score = score + 10;                // Any changes to score parameter won't affect the original value
    runnerLog("Inside function, score is: " + score);
    return 

returned value

If run in the SIL Manager, the function returns the following result:

Example description:

• First, the function gets a copy of the testScore = 75 value to work with.

• Inside the function, it adds 10 to that copy, making it 85. The function prints this value: "Inside function, score is: 85"

• After the function exits, both the original score (75) and the modified score (85) are printed.

Constant Parameters

Parameters of

UDFs can be made read-only

by using the const keyword within the function.

Example

function f(const string s) {
	...
}

Default Parameters

Parameters

can have defaults. This feature was introduced in

SIL v5.8.0.0.

The default value is used only when you don't provide a value for that parameter when calling the function. When you provide a value, it overrides the default.

Example

// Function with a default parameter - 'name' will use "Guest" if no value is provided
function greet(string name = "Guest") {
    runnerLog("Hello, " + name);
}

// You can call this function two ways:

// 1. Without providing a parameter - will use the default "Guest"
greet();                  // Outputs: "Hello, Guest"

// 2. Providing a value - will use your provided value instead of default
greet("John");           // Outputs: "Hello, John"

Variable visibility in UDFs

When writing UDFs, you can work with three different categories of variables:

• Local variables that you create inside the function

• Parameter variables that you pass into the function

• Global variables that are available throughout your program

Understanding how and when you can use each category of variable helps you write more effective and maintainable code.

function calculateTotal() {
    number 

Best practices for using variables in UDFs

• Keep in mind that local variables have the most limited access (just within the { and } of your UDF, while global variables have widest access.

• Minimize the use of global variables to reduce code complexity.

• Use meaningful parameter names to improve code readability.

• Document any global variables used within UDFs.

• Consider passing needed values as parameters rather than relying on their global state.

Return

value

When a UDF finishes running, it can send a value back to where it was called from. You can also use return to stop the UDR from running further. This way, return values serve two purposes:

• They provide a way to send results back to the code that called the UDF (like returning a calculation result.)

• They allow you to exit the UDF at any point (for example, stop early if an error is found.)

Examples

This example returns a boolean result:

function isEven(number 

value % 2 == 0);    // Returns true or false
}

This example returns a calculated value:

function increment(number 

    // result becomes 3

Important notes about returns

Return types are dynamic.

• SIL determines the return type at runtime, so there is no need to declare the return type

• in the UDF definition.

• You cannot return two different types. This represents an error

• Be careful with type compatibility when using the returned value. In the example below, the value of myDate will not be modified because there is an incompatibility between number (right-hand side, returned from the function) and date (left-hand side, the variable type).

  Code Block
  function increment(number

• value) { return

• value + 1; // Returns a number } date

• myDate = increment(2);

• // WARNING: This will fail at runtime // Cannot convert number to date

• A UDF can return at most one value.

• You can

• use return; without a value.

• UDFs always return a value, even if

• return is undefined. The

• result of empty returns is an undefined value.

Examples

These are examples of empty returns behavior:

function 

 Let's see what happens in each case:
string result1 = processStatus(150);    
// Prints: "Invalid: exceeds maximum"
// result1 is undefined because of empty return

string result2 = processStatus(-5);     
// Prints: "Invalid: negative value"
// result2 is undefined because of empty return

string result3 = processStatus(50);     
// Prints: "Processing: 50"
// result3 is undefined because of empty return

string result4 = processStatus(0);      
// Prints: "Status: inactive"
// result4 is undefined because function ends without return

// All results are undefined, so all these will print:
print("Result 1 is null");  // Prints for value 150
print("Result 2 is null");  // Prints for value -5
print("Result 3 is null");  // Prints for value 50
print("Result 4 is null");  // Prints for value 0

Best practices for return values

• Always consider what value your UDF should return.

• Be consistent with return types within a single UDF.

• Check for null/undefined values when using returned values.

• Use meaningful return values that help explain the UDF's outcome.