Lambdas (Java 8+) ayyuka ne marasa suna marasa kuskure, kuma karanar aiki na aiki shine karanar da sune daidai hanya daya ta baka — nau'in sani da lambda ya aiwata. Tare, sun kawo da aikin aiki ga Java kuma suna kara Stream API.
{
;
}
Karanar da take da hanya ɗaya ta baka ce ta "aiki" — lambda na iya ta aiwata saboda babu shakewa game da wane hanya lambda take.
// ❌ verbose anonymous class (pre-Java 8)
Calculator add = new Calculator() {
public int calculate(int a, int b) { return a + b; }
};
// ✅ lambda — same thing, far less boilerplate
Calculator add = (a, b) -> a + b;
Calculator multiply = (a, b) -> a * b;
add.calculate(2, 3); // 5
Lambda (a, b) -> a + b yana ba da aiwatarwa na hanya ɗaya — babu ajiya, babu boilerplate na signature na hanya.
Function<String, Integer> length = s -> s.length(); // takes T, returns R
Predicate<Integer> isPositive = n -> n > 0; // takes T, returns boolean
Consumer<String> printer = s -> System.out.println(s); // takes T, returns void
Supplier<String> greeting = () -> "Hello"; // takes nothing, returns T
BiFunction<Integer, Integer, Integer> sum = (a, b) -> a + b; // two args
Java yana ba da kafofin aiki da jita-jita na shirye-shirye don siffofin gida, waɗanda ake amfani da su a cikin dukkan matsakaicin lawalin karatu (musamman streams).
// when a lambda just calls an existing method, use a method reference
list.forEach(System.out::println); // instead of x -> System.out.println(x)
list.stream().map(String::toUpperCase); // instead of s -> s.toUpperCase()
list.stream().map(Integer::parseInt); // static method ref
// passing behavior as arguments — the core enabler of the Stream API
people.stream()
.filter(p -> p.getAge() > 18) // Predicate lambda
.map(Person::getName) // method reference
.forEach(System.out::println); // Consumer
list.sort((a, b) -> a.compareTo(b)); // Comparator lambda
button.addActionListener(e -> handleClick()); // event handler
Lambdas da kafofin aiki na aiki sun kawo da aikin aiki ga Java, wanda ya bugi fundamentally yadda abin da Java na zamani ake rubutu.
Suna share boilerplate na anonimasu kalasa na magana don wasa halayin azaman bayanai, wanda ke ba da damar taƙaitacce masu dakin abubuwa, masu kwatanta, masu karantawa, kuma — mafi mahimmi — duka Stream API (wanda ya dogara akan lambdas don ayyukansa filter/map/reduce).
Ana buƙatar fahimtar cewa lambda ta niye karanar aiki na aiki (hanya ɗaya ta baka), kafofin jita-jita (Function, Predicate, Consumer, Supplier), da alaƙar hanya ne dole ne a rubuce rubutun Java na zamani na modern kuma a yi amfani da streams, tarin, da APIs na haɗi a wuri.
Suna wakiltar babbar tasowa na harshe kuma suna mahimmin ciwon yanzu na Java.