What this snippet does
Generic types are treated as unknown shapes, preventing access to specific methods like toUpperCase without constraints.
Expected output
Compile Error: Property 'toUpperCase' does not exist on type 'T'.
Why practise typing this
Typing generics code builds muscle memory for the symbols and indentation TypeScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
More TypeScript practice
- Writing a basic identity functionGenerics · intermediate
- Creating a generic API fetcherGenerics · intermediate
- Defining a generic box interfaceGenerics · intermediate
- Defining a generic pagination responseGenerics · intermediate
- Using an interface without providing type argumentsGenerics · intermediate
- Constraining a generic to have a length propertyGenerics · intermediate