Type alias Strlen<S, Arr>

Get the length of a given string

Example

Strlen<'foo'>; // Result: 3
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Can be used to create type constraints on string lengths:

// Only allow strings of length 8-10 characters
type ValidPassword<T extends string> = Strlen<T> extends 8 | 9 | 10 ? T : never;

// Function that only accepts valid password strings
function checkValidPassword<T extends string>(val: T & ValidPassword<T>) {
  console.log(val);
}

// Works with string literals
const validPass = checkValidPassword('password123' as const); // OK
const invalidPass = checkValidPassword('short' as const); // Type error
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