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“MyInput”
是啥意思?
你自己定义了输入方法了?
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import java.io.*;
public class Jia{
    public static void main(String[] args) throws IOException{
    int i;
  float j;
    double k=0;
    System.out.println("请输入一个数");
    
    j=System.in.read();
    if(j>=1)
    {
    
    for(i=1;i<=j;i++)
    { 
      k+=1.0/(2*i-1);
    }
    System.out.println(k);
    
    }
    else 
    System.out.println("please enter a value >= 1");
    }        
}
你去试试这个
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import java.io.*;
public class Jia{
    public static void main(String[] args) throws IOException{
    int i = 0;
    double k=0;
    BufferedReader buf=new BufferedReader(new InputStreamReader(System.in));
    System.out.println("请输入一个数");
    String text = buf.readLine();
    
   
  if(Integer.parseInt(text)>=1)
    {
    
    for(i=1;i<=Integer.parseInt(text);i++)
    {
      k+=1.0/(2*i-1);
    
    }
    
    System.out.println(k);
    }
    else 
    System.out.println("please enter a value >= 1"); 
    }   
}
还可以用这个  我调试过了
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我用13楼的,可以编译.怎么回事,是什么问题?
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我是哪个地方出错啦
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14楼的可以编译,但用java运行出错.
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怎么又出错了啦
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是呀,新手学东西是很难呀.
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import java.io.*;
public class Jia{
    public static void main(String[] args) throws IOException{
    int i = 0;
    double k=0;
    BufferedReader buf=new BufferedReader(new InputStreamReader(System.in));
    System.out.println("请输入一个数");
    String text = buf.readLine();
    
   
  if(Integer.parseInt(text)>=1)
    {
    
    for(i=1;i<=Integer.parseInt(text);i++)
    {
      k+=1.0/(2*i-1);
    
    }
    
    System.out.println(k);
    }
    else 
    System.out.println("please enter a value >= 1"); 
    }   
}
还可以用这个  我调试过了
可以编译
运行结果是:
D:\javawork>javac jia.java
D:\javawork>java jia
Exception in thread "main" java.lang.NoClassDefFoundError: jia (wrong name: Jia)
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
4)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
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