What this snippet does
Strict mode enables a set of type-checking options that force developers to write safer, more predictable code.
Expected output
Compile Error: Variable 'x' is used before being assigned.
Why practise typing this
Typing tsconfig & compiler 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
- Strict null checks preventing undefined accesstsconfig & Compiler · intermediate
- Implicit any in function parameters under stricttsconfig & Compiler · intermediate
- Preventing null assignment to stringstsconfig & Compiler · intermediate
- Checking for null before accessing propertiestsconfig & Compiler · intermediate
- Array index access returns T instead of T | undefinedtsconfig & Compiler · intermediate
- Catching implicit any in variablestsconfig & Compiler · intermediate