if 选择结构
import java.util.Scanner;
public class if1 {
public static void main(String[] args) {
/*
if语句至多有1个else语句,else语句在所有的else if语句之后
if语句可以有若干个else if语句,他们必须在else语句之前;一旦其中一个else if语句检测为ture,
其它的else if以及else语句都将跳过执行
*/
Scanner scanner=new Scanner(System.in);
System.out.println("请输入成绩:");
int score=scanner.nextInt();
if (score==100){
System.out.println("恭喜满分");
} else if (score<100&&score>=90) {
System.out.println("A级");
}else if (score<90&&score>=80) {
System.out.println("B级");
} else if (score<80&&score>=70) {
System.out.println("C级");
} else if (score<70&&score>=60) {
System.out.println("D级");
} else if (score<60&&score>=0) {
}else {
System.out.println("成绩不合法"); }
scanner.close();
}}