Constant values

Reports expressions and conditions that always produce the same result, like true, false, null, or 0. Such expressions can be replaced with the corresponding constant value, or may indicate there is a bug in the code.

Examples:

  // always true
  // cause: || is used instead of &&
  if (x > 0 || x < 10) {}

  System.out.println(str.trim());
  // always false
  // cause: variable was dereferenced before null-check
  if (str == null) {}

The inspection's behavior may be controlled by annotations, such as nullability annotations, <a href="https://www.jetbrains.com.cn/en-us/help/idea/contract-annotations.html">@Contract</a> annotation, @Range annotation and so on.

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

ConstantValue

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Probable bugs

Configure the inspection:

Use the Don't report assertions with condition statically proven to be always true option to avoid reporting assertions that were statically proven to be always true. This includes conditions like if (alwaysFalseCondition) throw new IllegalArgumentException();.
Use the Ignore assert statements option to control how the inspection treats assert statements. By default, assertions are assumed to be executed (-ea mode). When the option is enabled, assertions will be ignored (-da mode).
Use the Warn when constant is stored in variable option to display warnings when a variable is used, whose value is known to be constant.

Before IntelliJ IDEA 2022.3, this inspection was part of the Constant Conditions & Exceptions inspection. This inspection has been split into two inspections: Constant Values and Nullability and data flow problems.

Inspection ID: ConstantValue

Inspection options

Here you can find the description of settings available for the Constant values inspection, and the reference of their default values.

Don't report assertions with condition statically proven to be always true

Option ID:

DONT_REPORT_TRUE_ASSERT_STATEMENTS

Default value:

Not selected

Ignore assert statements

Option ID:

IGNORE_ASSERT_STATEMENTS

Default value:

Not selected

Warn when constant is stored in variable

Option ID:

REPORT_CONSTANT_REFERENCE_VALUES

Default value:

Selected

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection ConstantValue

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.3

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.3, Qodana for JVM 2025.3,

Last modified: 03 December 2025