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: ReSharper analyzes values and nullability of symbols and suggests to eliminate expressions that are always true or always false.

The only problem with this inspection is that sometimes it's not obvious how ReSharper has come to this conclusion. Because of this, you may be unwilling to accept the ReSharper’s suggestion to replace an expression with explicit true or false, or to remove a redundant check in an if statement. 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 ReSharper to find more redundant comparisons and null checks in your code, use [NotNull], [NotNull], [ContractAnnotation] attributes to decorate your symbols or annotate external libraries you often use.