案例:
声明员工类Employee,包含属性:编号、姓名、年龄、薪资,
声明Test01测试类,并在main方法中,创建2个员工对象,并为属性赋值,并打印两个员工的信息。
public class Employee { private int number; private String name; private int age; private double salary; public Employee(){ } public Employee(int number,String name,int age,double salary){ this.number=number; this.name=name; this.age=age; this.salary=salary; } public void setAge(int age) { this.age = age; } public int getAge() { return age; } public void setNumber(int number) { this.number = number; } public int getNumber(){ return number; } public void setName(String name){ this.name=name; } public String getName(){ return name; } public void setSalary(double salary){ this.salary=salary; } public double getSalary(){ return salary; } public void printInfo(){ System.out.println("编号是:"+number+",年龄是:"+age+"姓名是:"+name+"薪资是:"+salary); } } package com.cwbjava.homework.homework_6.question_1; public class Test { public static void main(String[] args) { Employee employee = new Employee(); employee.setName("李白"); employee.setAge(18); employee.setNumber(1); employee.setSalary(2345.34); employee.printInfo(); Employee employee1 = new Employee(2, "李清照", 18, 265.9); employee1.printInfo(); } }
案例:
声明一个日期类MyDate,包含属性:年、月、日
声明一个Test02测试类,并在main方法中,创建3个日期对象,一个是你的出生日期,一个是毕业的日期,并打印显示
public class MyDate { private int year; private int month; private int day; public MyDate(int year, int month, int day) { this.year = year; this.month = month; this.day = day; } public MyDate() { } public int getYear() { return year; } public void setYeat(int yeat) { this.year = yeat; } public int getMonth() { return month; } public void setMonth(int month) { this.month = month; } public int getDay() { return day; } public void setDay(int day) { this.day = day; } @Override public String toString() { return "MyDate{" + "year年=" + year + ", month月=" + month + ", day=日" + day + '}'; } }
public class Test1 { public static void main(String[] args) { MyDate m1 = new MyDate(); m1.setYeat(1997); m1.setMonth(6); m1.setDay(14); System.out.println(m1); MyDate m2 = new MyDate(1997,3,14); System.out.println(m2); } }
public class Test1 { public static void main(String[] args) { MyDate m1 = new MyDate(); m1.setYeat(1997); m1.setMonth(6); m1.setDay(14); System.out.println(m1); MyDate m2 = new MyDate(1997,3,14); System.out.println(m2); } }
案例:
声明公民类Citizen,包含属性:姓名,生日,身份证号,其中姓名是String类型,生日是MyDate类型,身份证号也是String类型。
声明Test03测试类,在main方法中创建你们家庭成员的几个对象,并打印信息。
public class MyDate { private int year; private int month; private int day; public MyDate(int year, int month, int day) { this.year = year; this.month = month; this.day = day; } public MyDate() { } public int getYear() { return year; } public void setYeat(int yeat) { this.year = yeat; } public int getMonth() { return month; } public void setMonth(int month) { this.month = month; } public int getDay() { return day; } public void setDay(int day) { this.day = day; } @Override public String toString() { return "MyDate{" + "year年=" + year + ", month月=" + month + ", day=日" + day + '}'; } }
/** * 声明公民类Citizen,包含属性:姓名,生日,身份证号,其中姓名是String类型,生日是MyDate类型, * 身份证号也是String类型。 * 声明Test03测试类,在main方法中创建你们家庭成员的几个对象,并打印信息。 */ public class Citizen { private String name; private String id; private MyDate birthday; public Citizen(){ } public Citizen(String name, String id, MyDate birthday) { this.name = name; this.id = id; this.birthday = birthday; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getId() { return id; } public void setId(String id) { this.id = id; } public MyDate getBirthday() { return birthday; } public void setBirthday(MyDate birthday) { this.birthday = birthday; } @Override public String toString() { return "Citizen{" + "name='" + name + '\'' + ", id='" + id + '\'' + ", birthday=" + birthday + '}'; } }
/** * 声明Test03测试类,在main方法中创建你们家庭成员的几个对象,并打印信息。 */ public class Test2 { public static void main(String[] args) { Citizen c1 = new Citizen(); MyDate myDate = new MyDate(1997,6,14);// 较为复杂的形式进行赋值 c1.setBirthday(myDate); c1.setName("李白"); c1.setId("1348437583747"); System.out.println(c1); MyDate myDate1 = new MyDate(1998,8,17);// 最简洁的形式进行赋值 Citizen c2 = new Citizen("黄埔", "1034758585", myDate); System.out.println(c2); Citizen c3 = new Citizen();// 最复杂的形式进行变量赋值 MyDate myDate2 = new MyDate(); myDate2.setYeat(1997); myDate2.setMonth(5); myDate2.setDay(29); c3.setBirthday(myDate2); c3.setName("王冰冰"); c3.setId("19834849589"); System.out.println(c3); } }
案例:
声明一个日期类MyDate,包含属性:年、月、日,并在MyDate类中声明几个方法:
1、boolean isLeapYear():判断当前日期的是闰年吗?
2、void set(int y, int m, int d):修改年,月,日为新日期
3、void puls(int years, int months, int days):加上years年,months月,days天后的日期
并在测试类Test04的main方法中创建对象,并调用测试
/** * 声明一个日期类MyDate,包含属性:年、月、日,并在MyDate类中声明几个方法: * <p> * <p> * <p> * 2、void set(int y, int m, int d):修改年,月,日为新日期 * <p> * 3、void puls(int years, int months, int days):加上years年,months月,days天后的日期 * <p> * 并在测试类Test04的main方法中创建对象,并调用测试 */ public class MyDate { private int year; private int day; private int month; public MyDate(int year, int mongth, int day) { this.year = year; this.day = mongth; this.month = day; } public MyDate() { } public int getYear() { return year; } public void setYear(int year) { this.year = year; } public int getAge() { return day; } public void setAge(int age) { this.day = age; } public int getMonth() { return month; } public void setMonth(int month) { this.month = month; } @Override public String toString() { return "MyDate{" + "year年=" + year + ", month月=" + month + ", age日=" + day + '}'; } // 1.、boolean isLeapYear():判断当前日期的是闰年吗? public boolean isleapYear(int year) { if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {// 判断是闰年的标准 return true; } else { return false; } } // 2、void set(int y, int m, int d):修改年,月,日为新日期 public void set(int year, int month, int day) { this.year = year; this.month = month; this.day = day; } // 3、void puls(int years, int months, int days):加上years年,months月,days天后的日期 public void plus(int years,int months ,int days){ this.year+=years; this.month+=months; this.day+=days; while (day>28){// 从后面进行判断,此时天数有四种可能31 30 28 29 // 是大月 if(this.month==1||this.month==3||this.month==5||this.month==7||this.month==8||this.month==10||this.month==12){ day=day-31; month++; // 是是二月 }else if(month==2){ // 是闰年 if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0) {// 判断是闰年的标准 day=day-28; month++; // 是平年 } else { day=day-29; month++; } //是大月 }else if(this.month==4||this.month==6||this.month==9||this.month==11){ day=days-30; month++; } } // 月份是否增加 while (month>12){ month=months-12; year++; } } }
public class Test { public static void main(String[] args) { MyDate myDate = new MyDate(1997, 6, 25); System.out.println(myDate); boolean isleapYear = myDate.isleapYear(2000);// 判断是否是闰年 System.out.println(isleapYear); myDate.set(1888,3,5); System.out.println(myDate); myDate.plus(1,2,3); System.out.println(myDate); }
案例:
声明一个三角形类Triangle,包含属性:a,b,c,表示三条边,包含几个方法:
1、boolean isRightTriangle():判断是否是一个直角三角形
2、boolean isIsoscelesTriangle():判断是否是一个等腰三角形
3、boolean isEquilateralTriangle():判断是否是一个等边三角形
4、double getArea():根据三条边,用海伦公式求面积
5、double getLength():求周长
并在测试类Test05的main方法中调用测试
/** * 声明一个三角形类Triangle,包含属性:a,b,c,表示三条边,包含几个方法: * * 1、boolean isRightTriangle():判断是否是一个直角三角形 * * 2、boolean isIsoscelesTriangle():判断是否是一个等腰三角形 * * 3、boolean isEquilateralTriangle():判断是否是一个等边三角形 * * 4、double getArea():根据三条边,用海伦公式求面积 * * 5、double getLength():求周长 * * 并在测试类Test05的main方法中调用测试 */ public class Triangle { // 声明一个三角形类Triangle,包含属性:a,b,c,表示三条边,包含几个方法: private double a; private double b; private double c; public Triangle() { } public Triangle(double a, double b, double c) { this.a = a; this.b = b; this.c = c; } public double getA() { return a; } public void setA(double a) { this.a = a; } public double getB() { return b; } public void setB(double b) { this.b = b; } public double getC() { return c; } public void setC(double c) { this.c = c; } @Override public String toString() { return "Triangle{" + "a=" + a + ", b=" + b + ", c=" + c + '}'; } //1、boolean isRightTriangle():判断是否是一个直角三角形 public boolean isRightTriangle(){ if(a*a+b*b==c*c||a*a+c*c==b*b||c*c+b*b==a*a){ return true; } return false; } // //2、boolean isIsoscelesTriangle():判断是否是一个等腰三角形 public boolean idIsoscelesTriangle(){ if(a==b||a==c||b==c){ return true; } return false; } // //3、boolean isEquilateralTriangle():判断是否是一个等边三角形 public boolean isEquilateralTriangle(){ if(a==b&&a==c){ return true; } return false; } // //4、double getArea():根据三条边,用海伦公式求面积表达式为:S=√p(p-a)(p-b)(p-c), public double getArea(){ double p=(a+b+c)/2; return Math.sqrt(p*(p-a)*(p-b)*(p-c)); } // //5、double getLength():求周长 public double getLength(){ return a+b+c; } // // 并在测试类Test05的main方法中调用测试 }
public class Test2 { public static void main(String[] args) { Triangle t1 = new Triangle(10 ,10, 15); System.out.println(t1); boolean rightTriangle = t1.isRightTriangle();// 直角三角形 System.out.println("rightTriangle = " + rightTriangle); boolean idIsoscelesTriangle = t1.idIsoscelesTriangle();// 等腰直角三角形 System.out.println("idIsoscelesTriangle = " + idIsoscelesTriangle); boolean equilateralTriangle = t1.isEquilateralTriangle();// 判断是不是等边三角形 System.out.println("equilateralTriangle = " + equilateralTriangle); double area = t1.getArea();// 求面积 System.out.println("area = " + area); double length = t1.getLength();// 求周长 System.out.println("length = " + length); } }
案例:
声明一个数学计算工具类MathTools,包含如下方法:
1、int add(int a, int b):求a+b
2、int subtract(int a,int b):求a-b
3、int mutiply(int a, int b):求a*b
4、int divide(int a, int b):求a/b
5、int remainder(int a, int b):求a%b
6、int max(int a, int b):求a和b中的最大值
7、int min(int a, int b):求a和b中的最小值
8、boolean equals(int a, int b):判断a和b是否相等
9、boolean isEven(int a):判断a是否是偶数
10、boolean isPrimeNumer(int a):判断a是否是素数
11、int round(double d):返回d的四舍五入后的整数值
声明一个Test06测试类,并在main方法中调用测试
/** * ## 第6题 * <p> * 案例: * <p> * 声明一个数学计算工具类MathTools,包含如下方法: * <p> * 1、int add(int a, int b):求a+b * <p> * 2、int subtract(int a,int b):求a-b * <p> * 3、int mutiply(int a, int b):求a*b * <p> * 4、int divide(int a, int b):求a/b * <p> * 5、int remainder(int a, int b):求a%b * <p> * 6、int max(int a, int b):求a和b中的最大值 * <p> * 7、int min(int a, int b):求a和b中的最小值 * <p> * 8、boolean equals(int a, int b):判断a和b是否相等 * <p> * 9、boolean isEven(int a):判断a是否是偶数 * <p> * 10、boolean isPrimeNumer(int a):判断a是否是素数 * <p> * 11、int round(double d):返回d的四舍五入后的整数值 */ public class MathTool { private int a; private int b; public MathTool(int a, int b) { this.a = a; this.b = b; } public MathTool() { } public int getA() { return a; } public void setA(int a) { this.a = a; } public int getB() { return b; } public void setB(int b) { this.b = b; } public int add(int a, int b) { return a + b; } @Override public String toString() { return "MathTool{" + "a=" + a + ", b=" + b + '}'; } // ## 第6题 // //案例: // // 声明一个数学计算工具类MathTools,包含如下方法: // //1、int add(int a, int b):求a+b // //2、int subtract(int a,int b):求a-b public int subtract(int a, int b) { return a - b; } // //3、int mutiply(int a, int b):求a*b public int mutiply(int a, int b) { return a * b; } // //4、int divide(int a, int b):求a/b public int divide(int a, int b) { return a / b; } // //5、int remainder(int a, int b):求a%b public int remainder(int a, int b) { return a % b; } // //6、int max(int a, int b):求a和b中的最大值 public int max(int a, int b) { return a > b ? a : b; } // //7、int min(int a, int b):求a和b中的最小值 public int min(int a, int b) { return a > b ? b : a; } // //8、boolean equals(int a, int b):判断a和b是否相等 public boolean equals(int a, int b) { if (a == b) { return true; } return false; } // //9、boolean isEven(int a):判断a是否是偶数 public boolean isEvex(int a) { if (a % 2 == 0) { return true; } return false; } // //10、boolean isPrimeNumer(int a):判断a是否是素数 public boolean isPrimeNumer(int a) { boolean flag = true; for (int i = 2; i <= Math.sqrt(a); i++) {// 素数判断可以是一半也可以是根号数是素数的数学性质 if (a % i == 0) { flag=false; return flag; } } return flag; } // //11、int round(double d):返回d的四舍五入后的整数值 public int round(double d){ return (int)d; } }
public class Test { public static void main(String[] args) { MathTool tool = new MathTool(); int add = tool.add(12, 30); System.out.println("add = " + add); int subtract = tool.subtract(10, 34); System.out.println("subtract = " + subtract); int mutiply = tool.mutiply(10, 29); System.out.println("mutiply = " + mutiply); int divide = tool.divide(10, 2); System.out.println("divide = " + divide); int remainder = tool.remainder(9, 2); System.out.println("remainder = " + remainder); int max = tool.max(10, 20); System.out.println("max = " + max); int min = tool.min(20, 30); System.out.println("min = " + min); boolean equals = tool.equals(10, 10); System.out.println("equals = " + equals); boolean evex = tool.isEvex(20); System.out.println("evex = " + evex); boolean primeNumer = tool.isPrimeNumer(9); System.out.println("primeNumer = " + primeNumer); int round = tool.round(20.3); System.out.println("round = " + round); } }
案例:
声明一个数组管理工具类MyArrays,包含如下方法:
1、void sort(int[] arr):可以为任意一维整型数组arr实现从小到大排序
2、int indexOf(int[] arr, int value):可以在任意一维整型数组arr中查找value值的下标,如果不存在返回-1
3、int[] copy(int[] arr, int len):可以实现从任意一维数组arr中复制一个新数组返回,新数组的长度为len,从arr[0]开始复制
声明一个Test07测试类,并在main方法中调用测试
import java.util.Arrays; public class MyArrays { private int[]arr; public MyArrays(int[] arr) { this.arr = arr; } public MyArrays() { } public int[] getArr() { return arr; } public void setArr(int[] arr) { this.arr = arr; } @Override public String toString() { return "MyArrays{" + "arr=" + Arrays.toString(arr) + '}'; } // ## 第7题 // //案例: // // 声明一个数组管理工具类MyArrays,包含如下方法: // //1、void sort(int[] arr):可以为任意一维整型数组arr实现从小到大排序 public void sort(int[]arr){ boolean flag=true; l:for (int i = 0; i < arr.length-1; i++) { for (int j = 0; j < arr.length - 1 - i; j++) {// 防止下标越界,此外循环一次就可以少对比一次 if (arr[j]>arr[j+1]){ int temp=arr[j]; arr[j]=arr[j+1]; arr[j+1]=temp; flag=false; } if (flag==true){// 如果没有进行交换此时就直接结束循环 break l; } } } } // //2、int indexOf(int[] arr, int value):可以在任意一维整型数组arr中查找value值的下标,如果不存在返回-1 public int indexOf(int[]arr,int value){ int index=-1; for (int i = 0; i < arr.length; i++) { if ((arr[i]==value)){ index=i; return index; } } return index; } // //3、int[] copy(int[] arr, int len):可以实现从任意一维数组arr中复制一个新数组返回,新数组的长度为len,从arr[0]开始复制 // public int[] copy(int[]arr,int len){ int []str=new int[len]; for (int i = 0; i < len; i++) { str[i]=arr[i]; } return str; } // 声明一个Test07测试类,并在main方法中调用测试 } package com.cwbjava.homework.homework_6.question_7; public class Test { public static void main(String[] args) { int[]arr=new int[]{6,5,4,3,2,1}; MyArrays myArrays = new MyArrays(arr); System.out.println(myArrays); myArrays.sort(arr); System.out.println(myArrays); int i = myArrays.indexOf(arr, 4); System.out.println("i = " + i); int[] copy = myArrays.copy(arr,6); for (int i1 = 0; i1 < copy.length; i1++) { System.out.println(copy[i1]); } } }
案例:
声明一个常识工具类DateCommonsTools,包含如下方法:
1、String getWeekName(int week):根据星期值,返回对应的英语单词
2、String getMonthName(int month):根据月份值,返回对应的英语单词
3、int getTotalDaysOfMonth(int year, int month):返回某年某月的总天数
4、int getTotalDaysOfYear(int year):获取某年的总天数
5、boolean isLeapYear(int year):判断某年是否是闰年
声明一个Test08测试类,并在main方法中调用测试
// 案例:
//
// 声明一个常识工具类DateCommonsTools,包含如下方法:
public class DateCommonsTools { String getWeekName(int week) { switch (week) { case 1: return "Monday"; case 2: return "Tuesday"; case 3: return "Wednesday"; case 4: return "Thursday"; case 5: return "Friday"; case 6: return "Saturday"; case 7: return "Sunday"; default: return "你输入的星期错误!!!!!!"; } } //2、String getMonthName(int month):根据月份值,返回对应的英语单词 public String gerMonthName(int month){ switch (month){ case 1: return "january"; case 2: return "february"; case 3: return "march"; case 4: return "april"; case 5: return "may"; case 6: return "june"; case 7: return "july"; case 8: return "august"; case 9: return "september"; case 10: return "october"; case 11: return "novemeber"; case 12: return "december"; default: return "你输入的月份错误"; } } //3、int getTotalDaysOfMonth(int year, int month):返回某年某月的总天数 public int getTotalDaysOfMonth(int year,int month){ if(month==1||month==3||month==5||month==7||month==8||month==10||month==12){ return 31; } else if(month==2){ if (year%4==0&&year%100!=0||year%400==0){ return 28; }else { return 29; } }else if(month==4||month==6||month==9||month==11){ return 30; }else { return -1; } } // //4、int getTotalDaysOfYear(int year):获取某年的总天数 public int getTotalDaysOfYear(int year){ if (year%4==0&&year%100!=0||year%400==0){ return 364; } return 365; } // //5、boolean isLeapYear(int year):判断某年是否是闰年 boolean isLeapYear(int year){ if(year%4==0&&year%100!=0||year%400==0){ return true; } return false; } // // 声明一个Test08测试类,并在main方法中调用测试 } public class Test1 { public static void main(String[] args) { DateCommonsTools dateCommonsTools = new DateCommonsTools(); String weekName = dateCommonsTools.getWeekName(4); System.out.println("weekName = " + weekName); String s = dateCommonsTools.gerMonthName(9); System.out.println("s = " + s); int totalDaysOfYear = dateCommonsTools.getTotalDaysOfYear(1997); System.out.println("totalDaysOfYear = " + totalDaysOfYear); int totalDaysOfMonth = dateCommonsTools.getTotalDaysOfMonth(1997, 6); System.out.println("totalDaysOfMonth = " + totalDaysOfMonth); boolean leapYear = dateCommonsTools.isLeapYear(2000); System.out.println("leapYear = " + leapYear); } }