java 找不到标志
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Cannot find symbol
提问by edwinNosh
I'm getting the following java compiler errors:
我收到以下 Java 编译器错误：
main.java:9: cannot find symbol
symbol : method parseInt(int)
location: class java.lang.Integer
int count = Integer.parseInt(getPennies());
^
main.java:23: incompatible types
found : java.lang.String
required: int
JOptionPane.showInputDialog("How many pennies do you have?");
^
2 errors
2 错误
Here is my code
这是我的代码
import javax.swing.*;
class main {
public static void main(String args[]) {
try {
int count = Integer.parseInt(getPennies());
System.out.println("You have "+count+" pennies");
} catch (NumberFormatException exception) {
System.out.println("Please insert a number");
getPennies();
}
}
public static int getPennies() {
int input =
JOptionPane.showInputDialog("How many pennies do you have?");
return input;
}
}
Any idea why I am getting these errors?
知道为什么我会收到这些错误吗？
回答by Jon Skeet
Well, getPennies()returns an int, and there's no such method as Integer.parseInt(int)- the idea is that parseIntparses a string and givesyou an integer.
好吧，getPennies()返回一个int，并且没有这样的方法Integer.parseInt(int)- 这个想法是parseInt解析一个字符串并给你一个整数。
Then later you have:
然后你有：
int input = JOptionPane.showInputDialog("How many pennies do you have?");
... but showInputDialog returns a string, not an integer.
...但 showInputDialog 返回一个字符串，而不是一个整数。
You could fix both of these problems by changing getPennis() like this:
您可以通过像这样更改 getPennis() 来解决这两个问题：
public static String getPennies() {
return JOptionPane.showInputDialog("How many pennies do you have?");
}
Or:
或者：
public static int getPennies() {
String text = JOptionPane.showInputDialog("How many pennies do you have?");
return Integer.parseInt(text);
}
and removing the call to Integer.parseIntfrom the callerof getPennies().
和取出呼叫Integer.parseInt从主叫方的getPennies()。
回答by Alex
The method JOptionPane.showInputDialog()returns a Stringand not an int.
该方法JOptionPane.showInputDialog()返回 aString而不是 an int。
So you have a type incompatibility issue.
所以你有一个类型不兼容的问题。
回答by Evan Mulawski
Integer.parseIntrequires a Stringinput, not an int. Just use getPennies()without it. For the second error, showInputDialogreturns a String, so use the parseIntfunction there instead.
Integer.parseInt需要String输入，而不是int. getPennies()不用它就可以使用。对于第二个错误，showInputDialog返回 a String，因此请改用该parseInt函数。
回答by rsp
The parseInt()method parses a string to an integer, the input is done as a string, so changing the return type of getPennies()to a Stringwill probably do the job.
该parseInt()方法将字符串解析为整数，输入作为字符串完成，因此将返回类型更改getPennies()为 aString可能会完成这项工作。
