Study Java

리턴타입 : 재네릭 파라미터 타입 : 기본형 InFunction : public R apply(int value) DoubleFunction: public R apply(double value) LongFunction: public R apply(long value) import java.util.function.IntBinaryOperator; import java.util.function.IntFunction; public class IntFunctionTest { public static void main(String[] args) { IntFunction intFunction = new IntFunction() { @Override public String apply(int value) { ret..

Java 2020. 6. 21. 17:59

리턴타입 : int, double, long 파라미터 타입 : 제네릭 ToIntFunction : public int applyAsInt(T t) ToIntBiFunction : public int applyAsInt(T t, U u) ToDoubleFunction : public double applyAsDouble(T t) ToDoubleBiFunction : public double applyAsDouble(T t, U u) ToLongFunction : public long applyAsLong(T t) ToLongBiFunction : public long applyAsLong(T t, U u) import java.util.function.ToIntBiFunction; import java.u..

Java 2020. 6. 21. 17:10

AToBFunction A : 입력타입 B: 출력타입 IntToDoubleFunction : : public double applyAsDouble(int value) IntToLongFunction : public long applyAsDouble(int value) DoubleToIntFunction : public int applyAsDouble(double value) DoubleToLongFunction : public long applyAsDouble(double value) LongToIntFunction : public int applyAsDouble(long value) LongToDoubleFunction : public double applyAsDouble(long value) impo..

Java 2020. 6. 21. 16:52

1. int Type IntConsumer : public void accept(int value) intSupplier : public int getAsInt() IntPredicate : public boolean test(int value) IntUnaryOperator : int applyAsInt(int operand) IntBinaryOperator : public int applyAsInt(int left, int right) 2. double Type DoubleConsumer : public void accept(double value) DoubleSupplier : public double getAsDouble() DoublePredicate : public boolean test(do..

Java 2020. 6. 20. 18:03

import java.util.*; import java.util.function.BiFunction; public class replaceAllTest { /* replaceAll( BiFunction ) R apply(T t, U u) 구현 T : 현재 map의 key U : 현재 map의 value V : 메소드 수행 후 map의 value */ public static void main(String[] args) { Map map = new HashMap(); map.put("lee",22); map.put("lim",32); map.put("kim",34); map.put("park",44); map.replaceAll(new BiFunction() { @Override public Intege..

Java 2020. 6. 19. 22:08

import java.util.HashMap; import java.util.Map; import java.util.function.BiFunction; public class MergeTest { /* merge( key, value , BiFunction ) @Param1 : 메소드 작업의 수행 대상이 되는 map의 key @Param2 : map의 value와 같은 타입의 파라미터 전달 @Param3 : R apply(T t, U u) 구현 T : 현재 map의 value; U : @param2에서 전달 받은 value */ public static void main(String[] args) { Map map = new HashMap(); map.put("lee",22); map.put("lim"..

Java 2020. 6. 19. 20:50

import java.util.HashMap; import java.util.Map; import java.util.function.BiFunction; import java.util.function.Function; public class ComputIfPresentTest { /* computeIfPresent( key, BiFunction) @Param1 : map의 key @Param2 구현 메소드 : R apply(T t, U u) U : 현재 map의 key U : 현재 map의 value R : 메소드 수행 후 map의 value 값 */ public static void main(String[] args) { Map map = new HashMap(); map.put("lee",22); m..

Java 2020. 6. 19. 20:27

예제01 import java.util.HashMap; import java.util.Map; import java.util.function.Function; public class ComputeIfAbsentTest1 { /* computeIfAbsent( 맵의 키, Function ) 구현 메소드 : R apply(T t); 리턴값 R : map의 value 파라미터 T : map의 key */ public static void main(String[] args) { Map map = new HashMap(); map.put("java","java study"); map.put("jsp","JSP"); map.put("spring","스프링"); map.put("oracle","오라클"); map.c..

Java 2020. 6. 19. 20:01