JAVA 中的结构（顺序结构）

 public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("亲输入成绩");
        double sorce = scanner.nextDouble();
        if ( sorce==100 ){
            System.out.println("恭喜满分");
        }else if (sorce<100 && sorce>=90) {
            System.out.println("A");
        }else if (sorce<90 && sorce>=80){
            System.out.println("B");
        }else if (sorce<80 && sorce>=70){
            System.out.println("C");
        }else if (sorce<70 && sorce>=60){
            System.out.println("D");
        }else if (sorce<60 && sorce>=0){
            System.out.println("不及格");
        }
        else System.out.println("成绩不合法");
        scanner.close();

    }
}