os :windows7 x64 jdk:jdk-8u131-windows-x64 ide:Eclipse Oxygen Release (4.7.0) 代码: interface Say { public abstract void sayHello(); } class Javaer implements Say{ public void sayHello() { System.out.println("Java Hello"); } } class D
SICP 1.3.1 Procedures as Arguments,说明高阶函数之函数作为参数的原因:若干个函数拥有相似的算法或代码结构,对此加以抽象. (define (sum-integers a b) (if (> a b) 0 (+ a (sum-integers (+ a 1) b)))) (define (pi-sum a b) (if (> a b) 0 (+ (/ 1.0 (* a (+ a 2))) (pi-sum (+ a 4) b)))) 于是: 清单1: (defi