15.1. Lambda表达式标准语法

(参数列表) -> {
//Lambda表达式体
}

代码示例

Calculable.java

package com.a51cto.net;

public interface Calculable {
// 设计一个数值计算接口
 int calculateInt(int a , int b);

}

HelloWorld.java

package com.a51cto.net;

public class HelloWorld {
 public static void main(String[] args) {
  int n1 = 10;
  int n2 = 2;

  Calculable f1 = calculable('+');
  Calculable f2 = calculable('-');

  System.out.printf("%d + %d =%d\n",n1,n2,f1.calculateInt(n1, n2));
  System.out.printf("%d - %d =%d\n", n1,n2,f2.calculateInt(n1, n2));
 }
 public static Calculable calculable(char opr) {
  Calculable result;
  if (opr == '+') {
//   Lambda表达式实现Calculable接口
   result = (int a,int b) ->{
    return a + b;
   };

  } else {
   result = (int a,int b) ->{
    return a - b;
   };

  }
  return result;

 }

}