Return Values

public Decimal calculateDiscount(Decimal price, Decimal percentOff) {
    Decimal discountAmount = price * (percentOff / 100);
    return discountAmount;
}

Decimal savings = calculateDiscount(200, 15);
System.debug(savings); // 30

1. public Decimal calculateDiscount(Decimal price, Decimal percentOff) { — this time the return type is a real type, Decimal, not void.
2. Decimal discountAmount = price * (percentOff / 100); — computes the discount amount.
3. return discountAmount; — hands the computed value straight back to the caller. Unlike the void methods from earlier lessons, this one produces something usable.
4. } — closes the method.
5. (blank line)
6. Decimal savings = calculateDiscount(200, 15); — the returned value is stored in savings.
7. System.debug(savings); — logs 30.

public String classifyAge(Integer age) {
    if (age < 18) {
        return 'Minor';
    }
    return 'Adult';
}

1. public String classifyAge(Integer age) { — takes an age, returns a classification.
2. if (age < 18) { — checks whether the age is under 18.
3. return 'Minor'; — the moment return runs, the method ends right there — nothing after it in that path executes.
4. } — closes the if.
5. return 'Adult'; — only reached if line 2 was false — if age is 12, this line is never even reached, since line 3 already fired.
6. } — closes the method.

public Decimal calculateCommission(Decimal salePrice, Decimal commissionRate) {
    return salePrice * (commissionRate / 100);
}

Decimal commission = calculateCommission(1500000, 5);
System.debug(commission); // 75000

1. public Decimal calculateCommission(Decimal salePrice, Decimal commissionRate) { — takes the sale price and the commission rate as a percentage.
2. return salePrice * (commissionRate / 100); — computes and returns the commission in one step, without a separate variable.
3. } — closes the method.
4. (blank line)
5. Decimal commission = calculateCommission(1500000, 5); — calls it with a sale price and a 5% rate.
6. System.debug(commission); — logs 75000.

A real estate agent's commission calculation is exactly this shape: take inputs, compute one number, hand it back — clean, testable, and reusable for every sale.