Learn TypeScript in Your Browser
No setup required! Learn type-safe coding through interactive exercises
string
number
boolean
Primitive Types
Basic types like boolean, number, string
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type StringOrNumber =
string | number
Type Aliases
Give a new name to existing types
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number[]
Array<string>
Array Types
Array literals and type annotations
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let tuple:
[string, number]
Tuple Types
Arrays with fixed length and element types
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{ name: string;
age: number }
Object Types
Object literals and type annotations
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{ name: string;
age?: number }
Optional Properties
Define properties that can be omitted
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{ readonly name: string;
age: number }
Readonly Properties
Read-only properties
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💡 Learning Tips
- • First, run the code to check how it works
- • Read error messages carefully to understand what the problem is
- • It's important to think for yourself before viewing the solution
- • Try modifying the code to see how it behaves