20180626

JavaScript

下面两个函数的返回值是一样的吗？为什么？

function foo1() {
	return {
		bar: "hello"
	};
}

function foo2() {
    return
	{
		bar: "hello"
	};
}

不一样，第一个返回的是object,第二个返回的是undefined

return 、break、continue 等语句，如果后面紧跟换行，解析器一定会自动在后面填充分号（;）

MySQL

CREATE TABLE student_score(
		name VARCHAR(20),
		course VARCHAR(10),
		score INT(10)
);

INSERT  INTO  student_score VALUES('张三','语文',81);
INSERT  INTO  student_score VALUES('张三','数学',75);
INSERT  INTO  student_score VALUES('李四','语文',76);
INSERT  INTO  student_score VALUES('李四','数学',90);
INSERT  INTO  student_score VALUES('王五','语文',81);
INSERT  INTO  student_score VALUES('王五','数学',100);
INSERT  INTO  student_score VALUES('王五','英语',90);

SELECT name FROM student_score GROUP BY name HAVING MIN(score)>80;

Java

package test;

public class Client1 {
	public static double sumBallHeight(double h, int n) {
		if (n == 1)
			return h / 2;
		else
			return sumBallHeight(h / 2, n - 1);
	}

	public static void main(String[] args) {
		System.out.println(sumBallHeight(100, 10));
	} 
}