使用 lambda 表达式创建匿名类？

Question

Java 8 支持 lambda 表达式，我想知道我们是否可以用 lambda 表达式替换匿名类？

Answer 1

According to the Oracle docs on Lambda expressions, they are the same as anonymous classes implementing functional interfaces (interfaces having only one method).

So if you have a method which takes an argument which has a functional interface as its reference type, you can use a lambda expression while calling that method. Example:-

public boolean testString(Predicate<String> tester, String str);

When calling testString , you can make use of a lambda expression to reduce the amount of code needed to write a comparator:-

boolean result = testString(s -> { /* implement Predicate.test */}, str);

Why are lambda expressions useful?

When you want to leave the core functionality of a method to the caller without writing explicit classes/anonymous classes. Expanding the example taken above:-

boolean isStringPalindrome = testString(s -> { /* code to check if string is palindrome */}, "madam");
boolean doesStringContainVowels = testString(s -> { /* code to check if string contains vowels */}, "abc");