TypeScript Union Types

What are Union Types?

Union types allow a variable to hold multiple types.

Use the | symbol to define a union.

Using Union Types in Functions

Type Narrowing

Use conditions to determine the type before using it.

Union with Arrays

Union in Objects

Literal Union Types

Restrict values to specific options.

Full Example

Why Union Types are Important

• Allow flexible variables
• Improve type safety
• Used in APIs
• Common in real applications

Common Mistakes

• Not checking types before using values
• Using too many types
• Forgetting parentheses in arrays

Practice

Create a function that accepts a number or string and handles them differently.

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