javaLogic errorEasy

Double precision floating point currency rounding

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BugFind the bug and fix the code

What it should do

Sum item prices and return exact bill amount. Example: calculateTotalBill(0.1, 0.2) -> 0.3

What happens instead

0.1 + 0.2 produces 0.30000000000000004 due to IEEE 754 precision error

public class Main {
    public static double calculateTotalBill(double item1, double item2) {
        // Direct double addition accumulates floating point inaccuracies
        return item1 + item2;
    }

    public static void main(String[] args) {
        System.out.println(calculateTotalBill(0.1, 0.2));
    }
}

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

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This bug belongs to the logic errors pattern

The wrong operator, an inverted condition, a formula the right way round but backwards.

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public class Main { public static double calculateTotalBill(double item1, double item2) { // Direct double addition accumulates floating point inaccuracies return item1 + item2; } public static void main(String[] args) { System.out.println(calculateTotalBill(0.1, 0.2)); } }

Double precision floating point currency rounding

What it should do

What happens instead

More logic errors to practise

Double precision floating point currency rounding

What it should do

What happens instead

More logic errors to practise