Scripting: Math

Math in programming is actually much simpler than what you learned in school! You'll mostly be doing basic calculations like addition, subtraction, and maybe some multiplication. Don't worry - no complex formulas here!

Let's start with the basics and work our way up.

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Basic Math Operations

Setting Up Variables

First, let's create some variables to work with:

function onCreated() {
    temp.a = 2;
    temp.b = 4;
    temp.result = 0;
    echo("Result: " @ temp.result);
}

This will show Result: 0 because we haven't done any math yet.

Addition

Let's add our two numbers together:

function onCreated() {
    temp.a = 2;
    temp.b = 4;
    temp.result = temp.a + temp.b;
    echo("Result: " @ temp.result);
}

Output: Result: 6

Congratulations! You just performed your first mathematical operation in GraalScript.

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Math Operators

Here are all the basic math operators you can use:

Operator	Operation	Example	Result
+	Addition	5 + 3	8
-	Subtraction	5 - 3	2
*	Multiplication	5 * 3	15
/	Division	6 / 3	2
^	Exponents (Power)	2 ^ 3	8
%	Modulo (Remainder)	5 % 2	1

Examples of Each Operator

function onCreated() {
    temp.a = 10;
    temp.b = 3;

    echo("Addition: " @ temp.a @ " + " @ temp.b @ " = " @ (temp.a + temp.b));
    echo("Subtraction: " @ temp.a @ " - " @ temp.b @ " = " @ (temp.a - temp.b));
    echo("Multiplication: " @ temp.a @ " * " @ temp.b @ " = " @ (temp.a * temp.b));
    echo("Division: " @ temp.a @ " / " @ temp.b @ " = " @ (temp.a / temp.b));
    echo("Exponent: " @ temp.a @ " ^ " @ temp.b @ " = " @ (temp.a ^ temp.b));
    echo("Modulo: " @ temp.a @ " % " @ temp.b @ " = " @ (temp.a % temp.b));
}

Output:

Addition: 10 + 3 = 13
Subtraction: 10 - 3 = 7
Multiplication: 10 * 3 = 30
Division: 10 / 3 = 3.33333
Exponent: 10 ^ 3 = 1000
Modulo: 10 % 3 = 1

Understanding Modulo (%)

The modulo operator % gives you the remainder after division:

• 5 % 2 = 1 (because 5 ÷ 2 = 2 remainder 1)
• 8 % 3 = 2 (because 8 ÷ 3 = 2 remainder 2)
• 10 % 5 = 0 (because 10 ÷ 5 = 2 remainder 0)

This is useful for things like checking if a number is even or odd!

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Assignment Operators (Shortcuts)

Instead of writing temp.a = temp.a + 5, you can use shortcuts:

Operator	Long Form	Short Form	Description
+=	a = a + b	a += b	Add and assign
-=	a = a - b	a -= b	Subtract and assign
*=	a = a * b	a *= b	Multiply and assign
/=	a = a / b	a /= b	Divide and assign

Example: Using Assignment Operators

function onCreated() {
    temp.score = 100;
    echo("Starting score: " @ temp.score);

    temp.score += 50;  // Same as: temp.score = temp.score + 50
    echo("After bonus: " @ temp.score);

    temp.score -= 25;  // Same as: temp.score = temp.score - 25
    echo("After penalty: " @ temp.score);

    temp.score *= 2;   // Same as: temp.score = temp.score * 2
    echo("After doubling: " @ temp.score);
}

Output:

Starting score: 100
After bonus: 150
After penalty: 125
After doubling: 250

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Practical Examples

Example 1: Health and Damage System

function onCreated() {
    temp.maxHealth = 100;
    temp.currentHealth = temp.maxHealth;
    temp.damage = 25;

    echo("Player starts with " @ temp.currentHealth @ " health");

    temp.currentHealth -= temp.damage;
    echo("Player takes " @ temp.damage @ " damage");
    echo("Player now has " @ temp.currentHealth @ " health");

    if (temp.currentHealth <= 0) {
        echo("Player is dead!");
    } else {
        echo("Player is still alive");
    }
}

Example 2: Experience and Level System

function onCreated() {
    temp.currentExp = 250;
    temp.expPerLevel = 100;

    temp.playerLevel = temp.currentExp / temp.expPerLevel;
    temp.leftoverExp = temp.currentExp % temp.expPerLevel;

    echo("Player Level: " @ temp.playerLevel);
    echo("Experience towards next level: " @ temp.leftoverExp @ "/" @ temp.expPerLevel);
}

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Order of Operations

Just like in regular math, operations happen in a specific order:

1. Parentheses ()
2. Exponents ^
3. Multiplication and Division * / (left to right)
4. Addition and Subtraction + - (left to right)

Example: Using Parentheses

function onCreated() {
    temp.a = 2;
    temp.b = 3;
    temp.c = 4;

    // Without parentheses: 2 + 3 * 4 = 2 + 12 = 14
    temp.result1 = temp.a + temp.b * temp.c;
    echo("Without parentheses: " @ temp.result1);

    // With parentheses: (2 + 3) * 4 = 5 * 4 = 20
    temp.result2 = (temp.a + temp.b) * temp.c;
    echo("With parentheses: " @ temp.result2);
}

Output:

Without parentheses: 14
With parentheses: 20

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Practice Challenge

Try to figure out what values of temp.a and temp.b will make this script congratulate you:

function onCreated() {
    temp.a = 1;  // Change this value
    temp.b = 2;  // Change this value

    temp.a = temp.a - temp.b;
    temp.a = temp.a + 4;
    temp.b += temp.a;

    if (temp.a == 7 && temp.b == 10) {
        echo("You're awesome at math!");
    } else {
        echo("Not quite right. Try again!");
        echo("Current values - a: " @ temp.a @ ", b: " @ temp.b);
    }
}

Hint: Work through the math step by step:

1. What happens to temp.a after the subtraction?
2. What happens to temp.a after adding 4?
3. What happens to temp.b after adding temp.a to it?
4. What starting values would give you temp.a = 7 and temp.b = 10?

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Tips for Using Math in Scripts

1. Use meaningful variable names: temp.playerHealth is better than temp.h
2. Use parentheses when you're unsure about order of operations
3. Test your math with simple values first
4. Comment complex calculations to explain what they do

Math in GraalScript is a powerful tool for creating dynamic gameplay mechanics. Practice with these examples and you'll be calculating like a pro!