What this snippet does
By default, TypeScript assumes array access returns T even for out-of-bounds indices; noUncheckedIndexedAccess fixes this.
Expected output
undefined
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
- Enabling strict mode in tsconfigtsconfig & Compiler · intermediate
- 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
- Catching implicit any in variablestsconfig & Compiler · intermediate