如何在 Java 中将 lambda 表达式作为方法参数传递?
lambda 表达式是 Java 中的匿名或无名方法。它不会自行执行,用于实现函数式接口中声明的方法。如果我们想将 lambda 表达式作为方法参数传递给 Java,那么接收的方法参数类型必须为函数式接口类型。
示例
interface Algebra { int operate(int a, int b); } enum Operation { ADD, SUB, MUL, DIV } public class LambdaMethodArgTest { public static void main(String[] args) { print((a, b) -> a + b, Operation.ADD); print((a, b) -> a - b, Operation.SUB); print((a, b) -> a * b, Operation.MUL); print((a, b) -> a / b, Operation.DIV); } static void print(Algebra alg, Operation op) { switch (op) { case ADD: System.out.println("The addition of a and b is: " + alg.operate(40, 20)); break; case SUB: System.out.println("The subtraction of a and b is: " + alg.operate(40, 20)); break; case MUL: System.out.println("The multiplication of a and b is: " + alg.operate(40, 20)); break; case DIV: System.out.println("The division of a and b is: " + alg.operate(40, 20)); break; default: throw new AssertionError(); } } }
输出
The addition of a and b is: 60 The subtraction of a and b is: 20 The multiplication of a and b is: 800 The division of a and b is: 2
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