Menene Stream API?

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Menene Stream API?

Accepted Answer

**Stream API** (Java 8+) yana ba da damar **aiki mai salo** -tsarin sarrafa tarin — tacewa, canji, da tattarwa data ta hanyar jirgin aiki na ayyuka, wanda aka bayyana cikin gida (*menene* yi) maimakon zoben gida da bata (*yaya*). ## Imperative vs Stream style ```java // ❌ imperative — explicit loop, mutable accumulator List result = new ArrayList<>(); for (Person p : people) { if (p.getAge() >= 18) { result.add(p.getName().toUpperCase()); } } // ✅ stream — declarative pipeline, reads like a description of the transformation List result = people.stream() .filter(p -> p.getAge() >= 18) // keep adults .map(p -> p.getName().toUpperCase()) // extract + transform names .collect(Collectors.toList()); // gather into a list ``` Sanarwar jirgin yana bayyana niyya a bayyane azaman jirgin ayyuka, babu jirgin aiki na jiya ko accumulator. ## The pipeline structure ```text Source → Intermediate operations (lazy) → Terminal operation (triggers execution) ``` ```java stream() // source .filter(...) .map(...) // intermediate — lazy, return a new stream, chainable .collect(...) // terminal — produces a result, RUNS the pipeline ``` Ayyukan **tsakiya** (filter, map, sorted, distinct) sune **jajere** — suna gina jirgin aiki amma ba su aiki ba sai jirgin **ƙarshe** (collect, forEach, reduce, count) ya koda. ## Common operations ```java list.stream() .filter(x -> x > 0) // keep matching .map(x -> x * 2) // transform each .sorted() // sort .distinct() // remove duplicates .limit(10) // take first 10 .collect(Collectors.toList()); // aggregations int sum = nums.stream().mapToInt(Integer::intValue).sum(); long count = list.stream().filter(...).count(); Optional first = people.stream().filter(...).findFirst(); boolean any = list.stream().anyMatch(x -> x > 100); // grouping (very powerful) Map> byCity = people.stream().collect(Collectors.groupingBy(Person::getCity)); ``` ## reduce — fold to a single value ```java int total = nums.stream().reduce(0, (a, b) -> a + b); // sum via reduction ``` ## Parallel streams ```java list.parallelStream().filter(...).collect(...); // process across multiple cores // ⚠️ use only for large data + independent/stateless operations; measure first ``` ## Me yasa ya shafi Stream API ta canza yadda Java ta sarrafa data — jijiya wuyar da kula da zoben ruwan da aka bugi error da wuyar ayyuka, sanusi, wuri na cikin gida jirgin aiki don tacewa, tashe, warware, tara, da tattarwa. Ana amfani dasu sosai a Java na zamani don sarrafa data, yana sa niyya na code ya zubo, kuma ya haɗe da lambdas da refeshes hanya don salo na aiki. Janye lafiyar jajere tsakiya / kalmomi ƙarshe, ayyukan gida (filter/map/collect/reduce/groupingBy), da zaɓin jirgin jirgin (tare da su cavills) ya zama mahimmi don rubuta Java na zamani da yake dace. Jirginsu sune duka karawa ga aiki da bata mahimma ta jira, yana nuni da ilimin da ke jira Java.