Java學習筆記2（輸入與隨機數簡單介紹）
阿新 • • 發佈：2018-01-05
args image public 數據類型 system double next class gpo
public class RandomDemo{
public static void main(String[ ] args){
Random ran = new Random();
//0 - 49的隨機數
int i = ran.nextInt(50);
System.out.println(i);
//0.0 - 1.0的隨機小數
double d = ran.nextDouble();
System.out.println(d);
}
}
public static void main(String[] args){
byte b = 100;
System.out.println(b);
short s = 200;
System.out.println(s);
int i = 10000;
System.out .println(i);
long l = 100000000000L;
System.out.println(l);
float f = 3.14F;
System.out.println(f);
double d = 3.14;
System.out.println(d);
char c = ‘我‘;
System.out.println(c);
boolean bool = true;
System.out.println(bool);
}
}
輸入：
import java.util.Scanner;
public class ScannerDemo{
public static void main(String[ ] args){
Scanner sc = new Scanner(System.in);
int i = sc.nextInt();
System.out.println(i+1);
String s = sc.next();
System.out.println(s+1);
}
}
輸入1，輸出2，再輸入1，輸入11
隨機數：
import java.util.Random;
public class RandomDemo{
public static void main(String[ ] args){
Random ran = new Random();
//0 - 49的隨機數
int i = ran.nextInt(50);
System.out.println(i);
//0.0 - 1.0的隨機小數
double d = ran.nextDouble();
System.out.println(d);
}
}
如果想輸出1-50的隨機數，只需要i+1就可以了。
這裏簡要地介紹下java地數據類型：
public class Variable{
public static void main(String[] args){
byte b = 100;
System.out.println(b);
short s = 200;
System.out.println(s);
int i = 10000;
System.out .println(i);
long l = 100000000000L;
System.out.println(l);
float f = 3.14F;
System.out.println(f);
double d = 3.14;
System.out.println(d);
char c = ‘我‘;
System.out.println(c);
boolean bool = true;
System.out.println(bool);
}
}
java中的類型強制轉換與c中的一樣，不必多做介紹。
Java學習筆記2（輸入與隨機數簡單介紹）