An issue is raised when a conditional expression (with a condition determining which of two alternative expressions to evaluate) performs the same operation on both branches, differing only in the arguments.

In Java, this refers to the ternary operator with the syntax condition ? trueExpr : falseExpr.

Why is this an issue?

When both branches of a ternary operator apply the same function call or operation to different values, the code contains unnecessary duplication. This pattern makes the code harder to read because the common operation is stated twice instead of once.

Consider this example:

message = isError ? formatMessage(errorText) : formatMessage(warningText)

Here, the message formatting function appears in both branches. This duplication obscures the actual difference between the branches (the input value) and makes the code longer than necessary.

By moving the condition inside the function call, you highlight what actually varies:

message = formatMessage(isError ? errorText : warningText)

This refactored version:

• Eliminates repetition of the function call
• Makes the variable part (the condition) more visible
• Reduces the overall line length
• Improves readability by following the DRY (Don’t Repeat Yourself) principle

This pattern applies to function calls, object creation, array access, and other operations that are identical in both branches.

What is the potential impact?

This issue has a minor impact on code maintainability:

• Readability: Duplicated operations make code harder to scan and understand quickly
• Maintenance burden: If the operation needs to change, developers must update it in two places instead of one
• Code size: Unnecessary duplication increases the code footprint without adding value

How to fix it

Move the ternary operator inside the common method call or operation. The condition should determine which argument is passed, not which method is called.

Code examples

Noncompliant code example

String result = condition ? foo(a) : foo(b); // Noncompliant

Compliant solution

String result = foo(condition ? a : b);

Resources

Documentation

• Oracle Java Documentation - The Java Tutorials - Expressions, Statements, and Blocks
• Refactoring Guru - Simplifying Conditional Expressions