Error AtlasError Documentation and Resolution
Back to searchMore TypeScript errors

TypeScript

Property has no initializer and is not definitely assigned in the constructor

Property '{0}' has no initializer and is not definitely assigned in the constructor.

TypeScript found a class property that is declared as required but is not initialized at declaration time or guaranteed to be assigned in the constructor.

TS2564build

Observed message

Property '{0}' has no initializer and is not definitely assigned in the constructor.

Why it happens

  • A required class property is declared without a default value.
  • The constructor does not assign the property on every control path.
  • strictPropertyInitialization is enabled and the current class design does not satisfy it.

How to fix it

  1. Initialize the property where it is declared or assign it in the constructor.
  2. Mark the property optional only if the design allows it to be absent.
  3. Use a definite assignment assertion only when the property is guaranteed to be assigned before use.

Official reference

TSConfig Reference: strictPropertyInitialization

Related errors

TS2345Argument is not assignable to the parameter typeTS2540Cannot assign to read only propertyTS7016Could not find a declaration file for moduleTS2604JSX element type does not have any construct or call signatures

Explore more

TypeScriptBrowse more TypeScript errorsbuildBrowse more build errors
TS2564 Property has no initializer and is not definitely assigned: causes and fixes | Error Atlas