操作方法
头文件、定义函数、输出字符串、对变量赋值；定义输入的分数为“mark”，且分数会有小数 import java.util.Scanner;//头文件 class Mark{ public static void main(String[] args){ System.out.println("请输入一个分数");double mark; Scanner scanner = new Scanner(System.in); mark = scanner.nextDouble();
判断是否有输入错误。 if(mark<0||mark>100){ System.out.println("输入有误！ "); System.exit(0); }
判断分数的等级 90以上A， 80~89B，70~79分C，60~69D，60以下E if (mark>=90) System.out.println("this mark is grade \'A\' "); else if (mark>=80) System.out.println("this mark is grade \'B\' "); else if (mark>=70) System.out.println("this mark is grade \'C\' "); else if (mark>=60) System.out.println("this mark is grade \'D\' "); else System.out.println("this mark is grade \'E\' ");
完整代码 import java.util.Scanner; class Mark{ public static void main(String[] args){ System.out.println("请输入一个分数"); double mark; Scanner scanner = new Scanner(System.in); mark = scanner.nextDouble(); if(mark<0||mark>100){ System.out.println("输入有误！ "); System.exit(0); } if (mark>=90) System.out.println("this mark is grade \'A\' "); else if (mark>=80) System.out.println("this mark is grade \'B\' "); else if (mark>=70) System.out.println("this mark is grade \'C\' "); else if (mark>=60) System.out.println("this mark is grade \'D\' "); else System.out.println("this mark is grade \'E\' "); } }