What this snippet does
Explicitly typing 'this' ensures methods are only called in the correct context.
Expected output
1
Why practise typing this
Typing functions 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
- Basic function with typed argumentsFunctions · beginner
- Calculating tax with typed numbersFunctions · beginner
- Returning a string from a number functionFunctions · beginner
- Using a default parameter valueFunctions · beginner
- Sending an email with an optional subjectFunctions · beginner
- Placing a required parameter after an optional oneFunctions · beginner