/**
* lambda表达式
* Predicate<Integer>
* Function<Integer, Integer>
* Consumer<Integer>
* @author lenovo
*
*/
public class Test {
public static void main(String[] args) {
List<String> languages = Arrays.asList("Java", "Scala", "C++", "Haskell", "Lisp");
System.out.println("Languages which starts with J :");
filter(languages, (str)->((String) str).startsWith("J"));
System.out.println();
filter(languages, (str)->true);
System.out.println();
filter(languages, (str)->false);
System.out.println();
filter(languages, (str)->((String) str).length() > 4);
Predicate<String> startsWithJ = (n) -> n.startsWith("J");
filter(languages, startsWithJ);
System.out.println();
Predicate<String> fourLetterLong = (n) -> n.length() == 4;
filter(languages, fourLetterLong);
System.out.println();
Predicate<String> c = (n) -> n.endsWith("a");
filter2(languages, c);
int incr = 20; int myNumber = 10;
modifyTheValue(myNumber, val-> val + incr);
Function<Integer, Integer> function = val-> val + incr;
modifyTheValue(myNumber, function);
List<Integer> lt = Arrays.asList(1,3,8,12);
Predicate<Integer> c1 = (n) -> n > 3;
Function<Integer, Integer> m = i -> i*2;
Consumer<Integer> c2 = n -> System.out.println(n);
lt.stream().filter(c1)
.map(m).forEach(c2);
}
public static void filter(List<String> names, Predicate condition) {
for(String name: names) {
if(condition.test(name)) {
System.out.println(name + " ");
}
}
}
public static void filter2(List names, Predicate condition) {
names.stream().filter((name) -> (condition.test(name)))
.forEach((name) -> {System.out.println(name + " ");
});
}
static void modifyTheValue(int valueToBeOperated, Function<Integer, Integer> function){
int newValue = function.apply(valueToBeOperated);
System.out.println(newValue);
}
}
