λ

functions as values

var square = function(x) { return x * x };

var apply = function(data, func) { return func(data);}

console.log(apply(10, square));

Ang Java ay parangkami ng ex ko...

..wala paring closure.

- anon

Anonymous Inner ClassesCollections.sort(personList, new Comparator<Person>(){ public int compare(Person p1, Person p2){ return p1.firstName.compareTo(p2.firstName); }});

Anonymous Inner Classes

Lambda Expressions

Collections.sort(personList, new Comparator<Person>(){ public int compare(Person p1, Person p2){ return p1.firstName.compareTo(p2.firstName); }});

Collections.sort(personList, (Person p1, Person p2) -> p1.firstName.compareTo(p2.firstName));

Lambda Expressions

Lambda Exp. (shorter)

Collections.sort(personList, (Person p1, Person p2) -> p1.firstName.compareTo(p2.firstName));

Collections.sort(personList, (p1, p2) -> p1.firstName.compareTo(p2.firstName));

JEP 107Bulk Data Operations

for Collections(e.g filter/map/reduce)

filterList<Employee> old = new ArrayList<Employee>();

for (Employee e : employeeList) { if (e.age() > 60) { old.add(e); }}

filterList<Employee> old = new ArrayList<Employee>();

for (Employee e : employeeList) { if (e.age() > 60) { old.add(e); }}

List<Employee> old = employeeList.stream() .filter(e -> e.age() > 60) .collect( Collectors.toCollection( () -> new ArrayList<>() ) );

filterList<Employee> old = new ArrayList<Employee>();

for (Employee e : employeeList) { if (e.age() > 60) { old.add(e); }}

List<Employee> old = employeeList.stream() .filter(e -> e.age() > 60) .collect(Collectors.toCollection( () -> new ArrayList<>()));

filterList<Employee> old = new ArrayList<Employee>();

for (Employee e : employeeList) { if (e.age() > 60) { old.add(e); }}

List<Employee> old = employeeList.stream() .filter(e -> e.age() > 60) .collect( Collectors.toCollection( ArrayList::new ) );

filterList<Employee> old = new ArrayList<Employee>();

for (Employee e : employeeList) { if (e.age() > 60) { old.add(e); }}

List<Employee> old = employeeList.stream() .filter(e -> e.age() > 60) .collect(Collectors.toCollection(ArrayList::new));

filterList<Employee> old = new ArrayList<Employee>();

for (Employee e : employeeList) { if (e.age() > 60) { old.add(e); }}

List<Employee> old = employeeList.stream() .filter(e -> e.age() > 60) .collect(Collectors.toList());

mapList<String> names = new ArrayList<String>();

for (Employee e : employeeList) { names.add(e.firstName() + " " + e.lastName());}

mapList<String> names = new ArrayList<String>();

for (Employee e : employeeList) { names.add(e.firstName() + " " + e.lastName());}

List<String> names = employeeList.stream() .map(e -> e.firstName() + " " + e.lastName()) .collect(Collectors.toList());

reduceBigDecimal totalSalary = BigDecimal.ZERO;

for (Employee e : employeeList) { totalTax = totalTax.add(e.salary());}

reduceBigDecimal totalSalary = BigDecimal.ZERO;

for (Employee e : employeeList) { totalTax = totalTax.add(e.salary());}

BigDecimal totalSalary = employeeList.stream() .reduce(BigDecimal.ZERO, (sum, e) -> sum.add(e.salary()), (bd1, bd2) -> bd1.add(bd2));

reduceBigDecimal totalSalary = BigDecimal.ZERO;

for (Employee e : employeeList) { totalTax = totalTax.add(e.salary());}

BigDecimal totalSalary = employeeList.stream() .reduce(BigDecimal.ZERO, (sum, e) -> sum.add(e.salary()), BigDecimal::add);

chainingBigDecimal totalOldTax = employeeList.stream() .filter(e -> e.age() > 60) .map(e -> e.salary().multiply(e.taxRate())) .reduce(BigDecimal.ZERO, (sum, tax) -> sum.add(tax);

just like SQLBigDecimal totalOldTax = employeeList.stream() .filter(e -> e.age() > 60) .map(e -> e.salary().multiply(e.taxRate())) .reduce(BigDecimal.ZERO, (sum, tax) -> sum.add(tax);

SELECT SUM(salary * tax_rate)FROM employeesWHERE age > 60;

just like SQL

filter() => WHERE, GROUP BY

map() => SELECT, inline query

reduce() => aggregate functions

sort() => ORDER BY

λJava 8

Where to get LambdaProject Pagehttp://openjdk.java.net/projects/lambda/

JDK8http://jdk8.java.net/download.html

JDK8 w/ Lambdahttp://jdk8.java.net/lambda/

NetBeans Nightlyhttp://bertram2.netbeans.org:8080/job/jdk8lambda/lastSuccessfulBuild/artifact/nbbuild/

Thank you for listening!

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