传智播客 java基础 相关资料 Day1

package chuanzhiboke;import java.util.Scanner;/** * 2017-6-7  * 主题：分支语句练习。switch  if 实现分支 * 零散点： * 0、静态只读的声明语法  static final ****  ***=***; 集合的初始化需要参考别的文章 * 1、获取控制台输入  Scanner scan = new Scanner(System.in); * 2、字符串转换为整数  Integer.parseInt(“sfad”); 此时需要用try catch 包裹。否则可能出错。 * 3、控制台程序必须加入主函数  主函数必须带可憎的输入参数 * @author steven * */public class Day1 {/** * 程序功能提示语 */private static final String START_MSG = "输入0-100之间的数字，判断级别。输入exit退出程序。";/** * 退出提示语 */private static final String EXIT_MSG = "程序退出。";private static final String A_LEVEL = "A级";private static final String B_LEVEL = "B级";private static final String C_LEVEL = "C级";private static final String D_LEVEL = "D级";private static final String E_LEVEL = "E级";public static void main(String[] args) {convertInputToLevle();}/** * 处理输入，将输入的数字分级 */public static void convertInputToLevle(){Integer inputGrade = 0;String readContent = "";Scanner scan = new Scanner(System.in);showMsg(START_MSG);while (true) {readContent = scan.nextLine();if (readContent.equalsIgnoreCase("exit")) {showMsg(EXIT_MSG);scan.close();break;}try {inputGrade = Integer.parseInt(readContent);} catch (Exception e) {System.out.println(e.getMessage());showMsg(START_MSG);continue;}if (inputGrade >= 0 && inputGrade <= 100) {//switchTest(inputGrade);ifTest(inputGrade);} else {showMsg(START_MSG);}}}/** * 使用switch分级 * @param grade */public static void switchTest(Integer grade) {Integer convertGrade = grade / 10;switch (convertGrade) {case 10:showMsg(grade + " 属于 " + A_LEVEL);break;case 9:showMsg(grade + " 属于 " + A_LEVEL);break;case 8:showMsg(grade + " 属于 " + B_LEVEL);break;case 7:showMsg(grade + " 属于 " + C_LEVEL);break;case 6:showMsg(grade + " 属于 " + D_LEVEL);break;default:showMsg(grade + " 属于 " + E_LEVEL);break;}}/** * 使用if else 语句分级 * @param grade */public static void ifTest(Integer grade) {if (grade >= 90 && grade <= 100) {showMsg(grade + " 属于 " + A_LEVEL);return;}if (grade >= 80 && grade < 90) {showMsg(grade + " 属于 " + B_LEVEL);return;}if (grade >= 70 && grade < 80) {showMsg(grade + " 属于 " + C_LEVEL);return;}if (grade >= 60 && grade < 70) {showMsg(grade + " 属于 " + D_LEVEL);return;}if (grade >= 0 && grade < 60) {showMsg(grade + " 属于 " + E_LEVEL);return;}}/** * 输出提示公共函数 * @param msg */public static void showMsg(String msg) {System.out.println(msg);}}