第一关关键字
package step1;
public class KeyWord {
public static void main(String[] args) {
System.out.println("Hello world!");
}
}
第二关
标示符
package step2;
public class Identifier {
public static void main(String[] args) {
/********* Begin *********/
String s = "java实训";
int i =2;
System.out.println(s + i);
/********* End *********/
}
}
第三关ifelse分支
package step3;
import java.util.Scanner;
public class ifelse {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int grade = scanner.nextInt();
if(grade>=0&&grade<=59)
{
System.out.print("不及格");
}
else if(grade>=60&&grade<=75)
System.out.print("良好");
else if(grade>=76&&grade<=85)
System.out.print("优秀");
else if(grade>=86&&grade<=100)
System.out.print("非常优秀");
else
System.out.print(" 你输入的成绩有误!");
// ---------------------Begin------------------------
//0-59 -> 不及格
//60-75 -> 良好
//76-85 -> 优秀
//86-100 -> 非常优秀
// ---------------------End------------------------
}
}
第四关swich
package step4;
import java.util.Scanner;
public class SwitchCase {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int month = scanner.nextInt();
switch(month)
{
case 12: case 1: case 2:
System.out.print("当前为时间为冬季");
break;
case 3: case 4: case 5:
System.out.print("当前时间为春季");
break;
case 6: case 7: case 8:
System.out.print("当前时间为夏季");
break;
case 9: case 10: case 11:
System.out.print("当前时间为秋季");
break;
default:
System.out.print("输入的月份不正确!!!");
break;
}
// ---------------------Begin------------------------
//季节划分[12,1,2]=冬季.[3,4,5]= 春季, [6,7,8]=夏季,[9,10,11]= 秋季
// ---------------------End------------------------
}
}
第五关三元运算符
ackage step5;
import java.util.Scanner;
public class Threeyuan {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt();
int b = scanner.nextInt();
// ---------------------Begin------------------------
//将???的位置替换成3元表达式,要求a>=b时maxvalue=a,否则maxvalue=b
int maxvalue = a>=b?a:b;
// ---------------------End------------------------
System.out.println("两数中的最大值为:"+maxvalue);
}
}
第六关while循环
package step6;
import java.util.Scanner;
public class WhileCircle {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt();
int i=0;
while(i<=a)
{
System.out.println(i);
i++;
}
// ---------------------Begin------------------------
//使用while循环输出0-a的所有整数
// ---------------------End------------------------
}
}
第七关for循环
package step7;
import java.util.Scanner;
public class ForCircle {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int row = scanner.nextInt();
// ---------------------Begin------------------------
for(int i=1;i<=row;i++)
{
for(int j=1;j<=i;j++)
{
System.out.print("*");
}
System.out.println();
}
// ---------------------End------------------------
}
}