[問題]java新手 java.io 無法執行？
作者: ProGramE (SP_one) 2017-07-26 02:10:34
我是在 Eclipse 編輯 使用 java.io 卻發生問題 直接複製網路上的教學也是無法執行？
以下是我所編譯的
package pratice;
import java.io.*;
public class prac_ch03
{
public static void main(String args[])throws IOException
{
float height;
float weight;
System.out.println("Please input your height.");
height = keyin.readLine();
System.out.println("Please input your weight.");
weight = keyin.readLine();
System.out.println("Your BMI is :" + weight/(height*height));
}
}
執行出現：
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
keyin cannot be resolved
keyin cannot be resolved
at pratice.prac_ch03.main(prac_ch03.java:13)
請問是我忽略甚麼步驟以至於如此嗎？
在網路上尋找都找不到解答
麻煩各位！
以下是我所編譯的
package pratice;
import java.io.*;
public class prac_ch03
{
public static void main(String args[])throws IOException
{
float height;
float weight;
System.out.println("Please input your height.");
height = keyin.readLine();
System.out.println("Please input your weight.");
weight = keyin.readLine();
System.out.println("Your BMI is :" + weight/(height*height));
}
}
執行出現：
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
keyin cannot be resolved
keyin cannot be resolved
at pratice.prac_ch03.main(prac_ch03.java:13)
請問是我忽略甚麼步驟以至於如此嗎？
在網路上尋找都找不到解答
麻煩各位！
作者: storypp (隨風而逝的是一份真) 2017-07-26 02:26:00
沒看到你宣告keyin呀....
作者: james732 (好人超) 2017-07-26 09:13:00
你在哪裡看到keyin的用法的？
作者: gmoz ( This can't do that. ) 2017-07-26 10:15:00
複製貼上前也先該稍微看懂一下再貼吧你這個是連基本JAVA觀念都沒有，先補足基礎再開始吧
作者: jinn (阿昌) 2017-07-27 01:42:00
缺的keyin可能長這樣 ![]()
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" target="_blank" rel="nofollow">作者: hpbl (頂) 2017-08-23 13:50:00
Compiler給的錯誤訊息要會看啊...