import java.io.*;class Demo1128_1 { public static boolean isPrime(int in) { if(in%2==0&&in!=2)return false; if(in==1)return false; for(int i=3;i<Math.sqrt(in);i+=2) if (in%i==0)return false; return true; } public static void main(String[] args) throws IOException { int in=0; boolean Flag=true; String s; while(Flag) { System.out.println("Please input the number from 1 to 10000,0 to exit!"); BufferedReader c=new BufferedReader(new InputStreamReader(System.in)); s=c.readLine(); in=Integer.parseInt(s); if(in==0) Flag=false; else if(isPrime(in)) System.out.println(in+" is a prime number!"); else System.out.println(in+" isn't a prime number!"); } } }
你直接看一下system的类库 public int read(byte b[]) throws IOException { public int read(byte b[], int off, int len) throws IOException { public abstract int read() throws IOException; 这是3种读的方法!很清楚他是什么东西了! 那么println() public void println(long x) { ... ... 很多重载方法 你打印基本数据类型都可以! 阿且其他的飞机本类型你载println其实都有一个toString()方法的! 基本都可以println
{
public static boolean isPrime(int in)
{
if(in%2==0&&in!=2)return false;
if(in==1)return false;
for(int i=3;i<Math.sqrt(in);i+=2)
if (in%i==0)return false;
return true;
}
public static void main(String[] args)
throws IOException
{
int in=0;
boolean Flag=true;
String s;
while(Flag)
{
System.out.println("Please input the number from 1 to 10000,0 to exit!");
BufferedReader c=new BufferedReader(new InputStreamReader(System.in));
s=c.readLine();
in=Integer.parseInt(s);
if(in==0)
Flag=false;
else
if(isPrime(in))
System.out.println(in+" is a prime number!");
else
System.out.println(in+" isn't a prime number!");
}
}
}
public int read(byte b[]) throws IOException {
public int read(byte b[], int off, int len) throws IOException {
public abstract int read() throws IOException;
这是3种读的方法!很清楚他是什么东西了!
那么println()
public void println(long x) {
...
...
很多重载方法
你打印基本数据类型都可以!
阿且其他的飞机本类型你载println其实都有一个toString()方法的!
基本都可以println