toLowerCase

The toLowerCase() method returns a new string with all characters in lowercase.

Interactive example

Syntax

function toLowerCase<
	GenericInput extends string
>(
	input: GenericInput
): Lowercase<GenericInput>;

Parameters

• input: The string to modify. The type is generic (GenericInput extends string) to allow precise literal type inference.

Return value

A new string with all characters in lowercase. The return type is precisely inferred thanks to TypeScript's Lowercase<GenericInput> utility type.

See also

• toUpperCase
• capitalize
• uncapitalize

Sources

• MDN - String.prototype.toLowerCase() - JavaScript method used internally
• TypeScript - Lowercase<StringType> - TypeScript utility type for type inference