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Unnecessary Bit Operations Should Not Be Performed

High
correctnessperformance

What is it?​

This practice alerts on the use of unnecessary bit operations whose results are predictable and have no impact on the output.

Why apply it?​

Using these redundant operations increases code complexity without providing any benefit. It can make your code less efficient and more difficult to read and maintain.

How to fix it?​

Remove any unnecessary bit operations from your code. These include & -1, | 0, and ^ 0, which do nothing but clutter the code.

Examples​

Example 1:​

Negative​

The negative example uses | 0, which is unnecessary since it has no effect on the integer value.

public class BitOperation {
    public static int calculateValue(int a, int b) {
        return (a + b) | 0;  // Noncompliant
    }

    public static void main(String[] args) {
        System.out.println(calculateValue(5, 10));  // Output: 15
    }
}

Example 2:​

Positive​

The positive example demonstrates a calculation without using unnecessary bit operations, leading to cleaner and more efficient code.

public class BitOperation {
    public static int calculateValue(int a, int b) {
        return a + b;  // Compliant
    }

    public static void main(String[] args) {
        System.out.println(calculateValue(5, 10));  // Output: 15
    }
}

Negative​

The negative example utilizes ^ 0, which does not alter the value and unnecessarily complicates the code.

public class BitOperation {
    public static boolean isEven(int number) {
        return ((number % 2) == 0) ^ false;  // Noncompliant
    }

    public static void main(String[] args) {
        System.out.println(isEven(4));  // Output: true
    }
}

Example 3:​

Positive​

The positive example displays a logical operation that avoids redundant bit operations, maintaining clarity and performance.

public class BitOperation {
    public static boolean isEven(int number) {
        return (number % 2) == 0;  // Compliant
    }

    public static void main(String[] args) {
        System.out.println(isEven(4));  // Output: true
    }
}