Code Inspection: Expression is always 'true' or always 'false'

tip

You can suppress this inspection to ignore specific issues, change its severity level to make the issues less or more noticeable, or disable it altogether.

This inspection is fairly obvious: JetBrains Rider analyzes values and nullability, integer arithmetics, and so on, and suggests eliminating expressions that are always true or always false based on its analysis results.

The only problem with this inspection is that sometimes it's not obvious how JetBrains Rider has come to this conclusion. Because of this, you may be unwilling to accept suggestions to replace expressions with explicit true or false, or to remove a redundant checks in if statements. Below are some StackOverflow questions that illustrate this problem:

• Why does ReSharper tell me this expression is always true?

• How Does ReSharper Know “Expression is always true”?

• ReSharper bug? Incorrect “expression is always true”

• ReSharper claims that my expression is always true? Is it correct or is it a bug?

• ReSharper says this expression is always true. Why?

• Trying to understand why resharper told me expression is always false

• Why I getting an “Expression always true” warning?

tip

If you want JetBrains Rider to find more redundant comparisons and null checks in your code, use [NotNull], [ItemNotNull], [NonNegativeValue], and [ContractAnnotation] attributes to decorate your symbols or annotate external libraries you often use.