Comparison Using Wrong Factors

Incomplete Base

Structure: Simple

Description

The code performs a comparison between two entities, but the comparison examines the wrong factors or characteristics of the entities, which can lead to incorrect results and resultant weaknesses.

Extended Description

This can lead to incorrect results and resultant weaknesses. For example, the code might inadvertently compare references to objects, instead of the relevant contents of those objects, causing two "equal" objects to be considered unequal.

Common Consequences 1

Scope: Other

Impact: Varies by Context

Potential Mitigations 1

Phase: Testing

Thoroughly test the comparison scheme before deploying code into production. Perform positive testing as well as negative testing.

Demonstrative Examples 1

ID : DX-60

In the example below, two Java String objects are declared and initialized with the same string values. An if statement is used to determine if the strings are equivalent.

Code Example:Bad
Java
java

However, the if statement will not be executed as the strings are compared using the "==" operator. For Java objects, such as String objects, the "==" operator compares object references, not object values. While the two String objects above contain the same string values, they refer to different object references, so the System.out.println statement will not be executed. To compare object values, the previous code could be modified to use the equals method:

Code Example:Good
Java
java

Applicable Platforms

Languages:

Not Language-Specific : Undetermined

Modes of Introduction

Implementation

Related Weaknesses

ChildOf:

Incorrect Comparison (CWE-697)