10 TypeScript Errors Explained (30-Second Fixes)
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The ten TypeScript errors every developer hits — and the thirty-second fix for each one. If the
red squiggles in your editor feel like a foreign language, this walkthrough decodes the most common
TypeScript errors and shows you exactly how to clear them, with real code on screen for every fix.
We start with the one skill that unlocks all of them: how to read a TypeScript error message — the
file and line, the TS error code you can search, and the plain-English reason it fired. Then we go
through the big ten, one at a time:
TS2322 Type 'string' is not assignable to type 'number' — make the value match, or widen to a union.
TS2339 Property does not exist on type — add it to the interface, or narrow first.
TS2564 Property has no initializer — initialize it, mark it optional, or use definite assignment.
TS2304 Cannot find name — import it, install its types, or add "dom" to your tsconfig lib.
TS2554 Expected 2 arguments, but got 1 — pass the argument, or make the parameter optional.
Object is possibly 'undefined' (TS18048 / TS2532) — optional chaining, a nullish default, or a guard, not the non-null bang.
Cannot convert undefined or null to object — a runtime crash from Object.keys on null; guard or default it.
TS7053 implicit any from indexing — add an index signature or use Record.
TS2345 Argument is not assignable — match the argument type, and how it differs from TS2322.
Strict-mode wrap-up — why most TypeScript errors are strict mode doing its job, and why to enable it from day one.
Every snippet is copy-paste ready. Fix these while you type and they stay small; ignore them and
they pile up.
Full written guide and error hub:
https://generalistprogrammer.com/erro...
Get the printable cheat-sheet — TypeScript Mastery Pack ($19):
https://generalistprogrammer.gumroad....
— Chapters —
0:00 The 10 errors you'll actually hit
0:28 How to READ a TypeScript error
1:49 TS2322 — not assignable to type
3:00 TS2339 — property does not exist
4:14 TS2564 — no initializer
5:34 TS2304 — cannot find name
6:47 TS2554 — expected N arguments
7:56 Object is possibly 'undefined'
9:24 Cannot convert undefined or null to object
10:43 TS7053 — implicit any index
12:03 TS2345 — argument not assignable
13:17 Strict mode + cheat-sheet
— Title variants (A/B testing) —
1. 10 TypeScript Errors Explained (30-Second Fixes)
2. TypeScript Errors: 10 Fixes Every Dev Must Know
3. Fix 10 TypeScript Errors Fast (Beginner Guide)
#typescript #webdev #typescripterrors