# Package org.apache.commons.text.lookup

Provides algorithms for looking up strings for use with a `StringSubstitutor`.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  BiStringLookup<U> | Lookups a String key for a String value.
  StringLookup | Lookups a String key for a String value.

- Class Summary
  Class | Description
  --- | ---
  StringLookupFactory | Create instances of string lookups or access singleton string lookups implemented in this package.

- Enum Summary
  Enum | Description
  --- | ---
  DefaultStringLookup | An enumeration defining `StringLookup` objects available through `StringLookupFactory`.

## Package org.apache.commons.text.lookup Description

Provides algorithms for looking up strings for use with a `StringSubstitutor`. The main class in this package is `StringLookupFactory`.

Use `StringLookupFactory` to create instances of string lookups or access singleton string lookups. The main interface is `StringLookup` which is implemented here in package private classes.

Like `BiFunction` is a variant of `Function`, this `BiStringLookup` is a variant of `StringLookup`.

The initial implementation was adapted from Apache Commons Log4j 2.11.0.

Since:
  1.3

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