# Java flash cards: Freelancer level 49 Java terms at the Freelancer level, as flash cards. Updated: September 28, 2026 - [Study these as flash cards](https://www.ask-codey.com/decks/java/4/flash) - [Play Memory with them](https://www.ask-codey.com/games/memory?category=java&level=4) ## Terms in this deck - [ArrayList](https://www.ask-codey.com/glossary/arraylist): A resizable List backed by an array. - [Autoboxing](https://www.ask-codey.com/glossary/autoboxing): The compiler's automatic conversion from a primitive value to its wrapper object. - [Binary Search - Java](https://www.ask-codey.com/glossary/binary-search-java): A Binary Search is a searching algorithm used to search a collection or array. - [Bounded Wildcard](https://www.ask-codey.com/glossary/bounded-wildcard): A wildcard restricted to types above or below a stated type in the hierarchy. - [Build Tool](https://www.ask-codey.com/glossary/build-tool): Software that automates compiling, testing, packaging, and dependency resolution. - [collect()](https://www.ask-codey.com/glossary/collect): A terminal stream operation that gathers results into a collection or other container. - [Collection Framework](https://www.ask-codey.com/glossary/collection-framework): Java's standard interfaces and classes for storing and working with groups of objects. - [Comparable](https://www.ask-codey.com/glossary/comparable): An interface a class implements to define its natural ordering. - [Comparator](https://www.ask-codey.com/glossary/comparator): An object that defines an external ordering for values. - [Date-Time API](https://www.ask-codey.com/glossary/date-time-api): The java.time types for working with dates, times, durations, and time zones. - [Debugger](https://www.ask-codey.com/glossary/debugger): A tool for pausing a program and inspecting its execution state. - [Dependency](https://www.ask-codey.com/glossary/dependency): External code that a project needs to compile or run. - [Deque](https://www.ask-codey.com/glossary/deque-java): A double-ended queue that adds and removes elements at either end. - [filter()](https://www.ask-codey.com/glossary/filter-java): A stream operation that keeps only elements passing a test. - [Functional Interface](https://www.ask-codey.com/glossary/functional-interface): An interface with one abstract method that can be implemented by a lambda. - [Generics](https://www.ask-codey.com/glossary/generics): Type parameters that let classes and methods work safely with different reference types. - [Gradle](https://www.ask-codey.com/glossary/gradle): A build automation tool configured with Groovy or Kotlin scripts. - [HashMap](https://www.ask-codey.com/glossary/hashmap): A hash-based Map with no guaranteed iteration order. - [HashSet](https://www.ask-codey.com/glossary/hashset): A hash-based Set with no guaranteed iteration order. - [Intermediate Operation](https://www.ask-codey.com/glossary/intermediate-operation): A lazy stream operation that transforms or filters values and returns another stream. - [Iterator](https://www.ask-codey.com/glossary/iterator-java): An object that visits collection elements one at a time. - [JAR File](https://www.ask-codey.com/glossary/jar-file): A ZIP-based archive that packages Java classes and related resources. - [JUnit](https://www.ask-codey.com/glossary/junit): A popular Java framework for writing and running automated tests. - [Lambda Expression](https://www.ask-codey.com/glossary/lambda-expression): A compact function-like value that implements a functional interface. - [LinkedList](https://www.ask-codey.com/glossary/linkedlist): A List and Deque whose elements are connected as a chain of nodes. - [List](https://www.ask-codey.com/glossary/list-java): An ordered collection that allows duplicate elements and positional access. - [Logging](https://www.ask-codey.com/glossary/logging): Recording structured runtime events to help operate and diagnose software. - [Map](https://www.ask-codey.com/glossary/map-java): A collection that associates unique keys with values. - [map()](https://www.ask-codey.com/glossary/map-java-2): A stream operation that transforms each element into another value. - [Maven](https://www.ask-codey.com/glossary/maven): A build and dependency-management tool configured mainly with pom.xml. - [Method Reference](https://www.ask-codey.com/glossary/method-reference): A compact lambda form that points to an existing method with ::. - [Mock Object](https://www.ask-codey.com/glossary/mock-object): A controlled stand-in used to verify how code interacts with a dependency. - [Optional](https://www.ask-codey.com/glossary/optional): A container that explicitly represents either one non-null value or no value. - [Queue](https://www.ask-codey.com/glossary/queue): A collection designed to hold elements waiting to be processed. - [reduce()](https://www.ask-codey.com/glossary/reduce): A stream operation that combines elements into one result. - [Regular Expression](https://www.ask-codey.com/glossary/regular-expression-java): A text pattern used to find, validate, or replace matching characters. - [Set](https://www.ask-codey.com/glossary/set-java): A collection that does not keep duplicate elements. - [Stream](https://www.ask-codey.com/glossary/stream): A pipeline for processing a sequence of values without storing the values itself. - [Stream Pipeline](https://www.ask-codey.com/glossary/stream-pipeline): A stream source followed by intermediate operations and one terminal operation. - [Terminal Operation](https://www.ask-codey.com/glossary/terminal-operation): A stream operation that produces a result or side effect and ends the pipeline. - [Test Fixture](https://www.ask-codey.com/glossary/test-fixture-java): The known objects and data prepared for a test. - [TreeMap](https://www.ask-codey.com/glossary/treemap): A Map that keeps its keys sorted. - [TreeSet](https://www.ask-codey.com/glossary/treeset): A sorted Set that keeps elements in their natural or supplied order. - [Type Erasure](https://www.ask-codey.com/glossary/type-erasure): The compiler process that removes most generic type details from runtime bytecode. - [Type Parameter](https://www.ask-codey.com/glossary/type-parameter): A placeholder type declared by a generic class, interface, or method. - [Unboxing](https://www.ask-codey.com/glossary/unboxing): The compiler's automatic conversion from a wrapper object to its primitive value. - [Unit Test](https://www.ask-codey.com/glossary/unit-test): A small automated check of one focused unit of behavior. - [Wildcard Type](https://www.ask-codey.com/glossary/wildcard-type): A ? type argument representing an unknown reference type. - [Wrapper Class](https://www.ask-codey.com/glossary/wrapper-class): An object type corresponding to a primitive, such as Integer for int. [Read them in the glossary](https://www.ask-codey.com/glossary/subjects/java/freelancer) Source: https://www.ask-codey.com/decks/java/freelancer