Swazi Functions in Control Flow

Quick Recap: Functions (kazi)

Functions ("kazi") are the foundation of reusable code in SwaziLang. You already know how to define and use them, but let's quickly recall why they're so important for control flow:

• Encapsulation: Functions let you group related logic, making code easier to read and manage.
• Decision Making: You can use functions to wrap conditional logic (kama/vinginevyo), so decisions are reusable.
• Loop Helpers: Functions often power loops, letting you process arrays and collections efficiently.

---

Functions in Control Flow

1. Using Functions in Conditions

You can call a function inside any SwaziLang conditional (kama, vinginevyo kama, vinginevyo):

kazi isAdult age {
    rudisha age >= 18;
}

data userAge = 20;

kama isAdult(userAge) {
    chapisha "User is an adult";
} vinginevyo {
    chapisha "User is not an adult";
}

---

2. Early Returns to Control Flow

Inside a function, you can use rudisha to exit early if a condition is met:

kazi processData value {
    kama value sawa null {
        chapisha "No value provided!";
        rudisha null;
    }
    chapisha "Processing: " + value;
}

---

3. Functions as Loop Helpers

Many loops are powered by functions—especially when processing arrays:

kazi printItem fruit {
    chapisha "fruit: " + fruit;
}

data fruits = ["apple", "banana", "orange"];

kwa kila fruit katika fruits:
    printItem(fruit)

---

4. Returning Values to Drive Control Flow

The result of a function can be used to decide what happens next:

kazi scoreStatus score {
    kama score >= 50 {
        rudisha "pass";
    }
    rudisha "fail";
}

data result = scoreStatus(75);

kama result sawa "pass" {
    chapisha "Congratulations!";
} vinginevyo {
    chapisha "Try again!";
}

---

Block Styles Reminder

SwaziLang lets you use C-style ({}) or Pythonic style (: and indentation) for function bodies and control blocks.
Pick the style that suits you, but keep indentation correct for Pythonic blocks!

kazi greet name {
    chapisha "Hello, " + name;
}
// or
kazi greet name :
    chapisha "Hello, " + name

---

Practice Challenge

Write a function that checks if a number is even, then use it in a conditional.

Solution

kazi isEven n {
    rudisha n % 2 sawa 0;
}

data num = 7;

kama isEven(num) {
    chapisha "Even";
} vinginevyo {
    chapisha "Odd";
}

---

Function Parameters

• kazi functions
  • Define parameters without parentheses.

    kazi add a, b {
        rudisha a + b;
    }

  • Call with parentheses:

    add(5, 6)

INFO

As per version 2.3.0+ you can wrap parameters in kazi statements with parentheses.

• Lambda functions

  • One parameter: No parentheses needed.

    data double = x => x * 2

  • More than one: Parentheses required.

    data sum = (a, b) => a + b

• tabia methods (in objects/classes)

  • Parentheses for parameters are allowed.

    tabia add(a, b) { ... }
    tabia show() { ... }

  • Or without parentheses:

    tabia print x, y { ... }

Null Value

• SwaziLang uses null for "no value"/empty/nothing.

---

Summary:

• Define kazi parameters without parentheses.
• Use parentheses for lambda with multiple params, and for tabia if you wish.
• Always use null for empty values.

Summary

• SwaziLang functions (kazi) are essential for organizing control flow.
• Use them inside conditions and loops to make code reusable and clean.
• Return values from functions to help guide your program's decisions.
• Mix and match block styles, but keep them consistent!

Next: Dive deeper into Swazi lambda functions for powerful, flexible control flow!