很详细的帮你写下,呵呵,所以要给分哦!
1、
(1)源程序如下:
public class One {
public static void main(String[] args) {
String name = "张三";
int age = 23;
char sex = '男';
String myclass = "某某专业2班";
System.out.println("姓名:" + name);
System.out.println("姓名:" + age);
System.out.println("姓名:" + sex);
System.out.println("姓名:" + myclass);
}
}
(2)
编写完程序的后缀名是.java,如本题,文件名就是One.java。
开始\运行\cmd,进入“命令提示符窗口”,然后用javac编译器编译.java文件,语句:javac One.java。
(3)
编译成功后,生成的文件名后缀是.class,叫做字节码文件。再用java解释器来运行改程序,语句:java One
2、编写程序,输出1到100间的所有偶数
(1)for语句
public class Two1 {
public static void main(String[] args) {
for(int i=2;i<=100;i+=2)
System.out.println(i);
}
}
(2)while语句
public class Two2 {
public static void main(String[] args) {
int i = 2;
while (i <= 100) {
System.out.println(i);
i += 2;
}
}
}
(3)do…while语句
public class Two3 {
public static void main(String[] args) {
int i = 2;
do {
System.out.println(i);
i += 2;
}while(i<=100);
}
}
3、编写程序,从10个数当中找出最大值。
(1)for循环
import java.util.*;
public class Three1 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int number;
int max = 0;
for (int i = 0; i < 10; i++) {
System.out.print("输入第" + (i + 1) + "个数:");
number = input.nextInt();
if (max < number)
max = number;
}
System.out.println("最大值:" + max);
}
}
(2)while语句
import java.util.*;
public class Three2 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int number;
int max = 0;
int i = 0;
while (i < 10) {
System.out.print("输入第" + (i + 1) + "个数:");
number = input.nextInt();
if (max < number)
max = number;
i++;
}
System.out.println("最大值:" + max);
}
}
(3)do…while语句
import java.util.*;
public class Three3 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int number;
int max = 0;
int i = 0;
do {
System.out.print("输入第" + (i + 1) + "个数:");
number = input.nextInt();
if (max < number)
max = number;
i++;
}while(i<10);
System.out.println("最大值:" + max);
}
}
4、编写程序,计算从1到100之间的奇数之和。
(1)for循环
public class Four1 {
public static void main(String[] args) {
int sum=0;
for(int i = 1;i<=100;i+=2){
sum+=i;
}
System.out.println("1~100间奇数和:" + sum);
}
}
(2)while语句
public class Four2 {
public static void main(String[] args) {
int sum = 0;
int i = 1;
while (i <= 100) {
sum += i;
i += 2;
}
System.out.println("1~100间奇数和:" + sum);
}
}
(3)do…while语句
public class Four3 {
public static void main(String[] args) {
int sum = 0;
int i = 1;
do {
sum += i;
i += 2;
} while (i <= 100);
System.out.println("1~100间奇数和:" + sum);
}
}
5、
(1)什么是类的继承?什么是父类?什么是子类?举例说明。
继承:是面向对象软件技术当中的一个概念。如果一个类A继承自另一个类B,就把这个A称为"B的子类",而把B称为"A的父类"。继承可以使得子类具有父类的各种属性和方法,而不需要再次编写相同的代码。在令子类继承父类的同时,可以重新定义某些属性,并重写某些方法,即覆盖父类的原有属性和方法,使其获得与父类不同的功能。另外,为子类追加新的属性和方法也是常见的做法。继承需要关键字extends。举例:
class A{}
class B extends A{}
//成员我就不写了,本例中,A是父类,B是子类。
(2)编写一个继承的程序。
class Person {
public String name;
public int age;
public char sex;
public Person(String n, int a, char s) {
name = n;
age = a;
sex = s;
}
public void output1() {
System.out.println("姓名:" + name + "\n年龄:" + age + "\n性别:" + sex);
}
}
class StudentPerson extends Person {
String school, department, subject, myclass;
public StudentPerson(String sc, String d, String su, String m, String n,
int a, char s) {
super(n, a, s);
school = sc;
department = d;
subject = su;
myclass = m;
}
public void output2() {
super.output1();
System.out.println("学校:" + school + "\n系别:" + department + "\n专业:"
+ subject + "\n班级:" + myclass);
}
}
public class Five2 {
public static void main(String[] args) {
StudentPerson StudentPersonDemo = new StudentPerson("某某大学", "某某系别",
" 某专业", "某某班级", " 张三", 23, '男');
StudentPersonDemo.output2();
}
}