java - 错误：<标识符> 预期
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java - error: <identifier> expected
提问by VVMC23
I am trying to learn java with this website: http://www.homeandlearn.co.uk/java/user_input.htmlBut when I run the code in Ubuntu through the terminal I get these errors:
我正在尝试通过以下网站学习 Java：http: //www.homeandlearn.co.uk/java/user_input.html但是当我通过终端在 Ubuntu 中运行代码时，出现以下错误：
vonvic@BSW-Computer:~/Java_Applications$ javac StringVariables2.java
StringVariables2.java:3: error: '{' expected
public static class main(String[] args) {
^
StringVariables2.java:8: error: <identifier> expected
System.out.println("Please enter your first name")
^
StringVariables2.java:8: error: illegal start of type
System.out.println("Please enter your first name")
^
StringVariables2.java:8: error: ';' expected
System.out.println("Please enter your first name")
^
StringVariables2.java:12: error: <identifier> expected
System.out.println("Please enter your family name")
^
StringVariables2.java:12: error: illegal start of type
System.out.println("Please enter your family name")
^
StringVariables2.java:12: error: ';' expected
System.out.println("Please enter your family name")
^
StringVariables2.java:16: error: <identifier> expected
full_name = first_name +" "+ family_name;
^
StringVariables2.java:18: error: <identifier> expected
System.out.println("You are" + full_name);
^
StringVariables2.java:18: error: illegal start of type
System.out.println("You are" + full_name);
^
StringVariables2.java:18: error: ')' expected
System.out.println("You are" + full_name);
^
StringVariables2.java:18: error: ';' expected
System.out.println("You are" + full_name);
^
StringVariables2.java:18: error: illegal start of type
System.out.println("You are" + full_name);
^
StringVariables2.java:18: error: <identifier> expected
System.out.println("You are" + full_name);
^
StringVariables2.java:18: error: ';' expected
System.out.println("You are" + full_name);
^
StringVariables2.java:20: error: reached end of file while parsing
}
^
16 errors
vonvic@BSW-Computer:~/Java_Applications$
Here is the code:
这是代码：
import java.util.Scanner;
public class StringVariables2 {
public static class main(String[] args) {
Scanner user_input = new Scanner( System.in );
String first_name;
System.out.println("Please enter your first name")
first_name = user_input.next();
String first_name;
System.out.println("Please enter your family name")
first_name = user_input.next()
String full_name;
full_name = first_name +" "+ family_name;
System.out.println("You are" + full_name);
}
}
I'm using Ubuntu 13.10 Saucy Salamander.
我正在使用 Ubuntu 13.10 Saucy Salamander。
Now I get this:
现在我明白了：
vonvic@BSW-Computer:~/Java_Applications$ javac StringVariables2.java
StringVariables2.java:13: error: variable first_name is already defined in method main(String[])
String first_name;
^
StringVariables2.java:18: error: cannot find symbol
full_name = first_name + " " + family_name;
^
symbol: variable family_name
location: class StringVariables2
2 errors
回答by d.moncada
Looks like you forgot to add semi-colons to the end of some of your statements:
看起来您忘记在某些语句的末尾添加分号：
System.out.println("Please enter your first name");
System.out.println("Please enter your family name");
first_name = user_input.next();
Edit:
编辑：
Your mainshould also be a method (not a class)
你main也应该是一个方法（不是一个类）
public static void main(String[] args)
回答by Patricia Shanahan
You need to declare main as a method, not a class:
您需要将 main 声明为方法，而不是类：
public static void main(String[] args)
Declaring main as a class put several executable statements at the top level inside that class, where only declarations are permitted.
将 main 声明为一个类，在该类的顶层放置了几个可执行语句，其中只允许声明。
