使用扫描仪类在 Java 中读取字符串输入的问题
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Issues reading string input in Java with scanner class
提问by Barney G
I'm pretty much a complete newbie when it comes to Java. I've dabbled a bit in python and VB.net, and that's about it.
当谈到 Java 时，我几乎是一个完整的新手。我在 python 和 VB.net 中有所涉猎，仅此而已。
I'm trying to write a program in java that literally reads the user's input and displays it back to them with this code:
我正在尝试用 Java 编写一个程序，该程序从字面上读取用户的输入并使用以下代码将其显示给他们：
import java.util.Scanner;
public class InputTesting
{
public static void main( String[] args )
{
Scanner input = new Scanner ( System.in );
String str1;
System.out.println("Input string: ");
str1 = input.nextString();
System.out.println( str1 );
}
}
And I get the error:
我得到错误：
InputTesting.java:13: error: cannot find symbol
str1 = input.nextString();
^
symbol: method nextString()
location: variable input of type Scanner
1 error
Can someone tell what why it's not compiling? Thanks!
有人能说出为什么它没有编译吗？谢谢！
采纳答案by christopher
input.nextString();
There is no method called nextStringin the Scannerclass. That's why you're getting the error cannot find symbol.
没有调用方法nextString的Scanner类。这就是您收到错误的原因cannot find symbol。
Try
尝试
input.nextLine(); // If you're expecting the user to hit enter when done.
input.next(); // Just another option.
回答by Rakesh KR
import java.util.Scanner;
public class InputTesting
{
public static void main( String[] args )
{
Scanner input = new Scanner ( System.in );
String str1;
System.out.println("Input string: ");
str1 = input.next();
System.out.println( str1 );
}
}
回答by Prashant Bhate
You may use one of input.nextXXX()as detailed in Scanner javadoc. to resolve compiler error
您可以使用Scanner javadoc 中input.nextXXX()详述的其中之一。解决编译器错误
in your case
在你的情况下
you may use input.nextLine();get entire line of text.
您可以使用input.nextLine();获取整行文本。
By Default whitespace delimiter used by a scanner. However If you need to scan sequence of inputs separated by a delimiter useDelimitercan be used to set regex delim
默认情况下，扫描仪使用的空白分隔符。但是，如果您需要扫描由分隔符分隔的输入序列，useDelimiter可用于设置正则表达式 delim
public static void main(String[] args) {
try (Scanner input = new Scanner(System.in);) {
input.useDelimiter(";");
while (input.hasNext()) {
String next = input.next();
if ("DONE".equals(next)) {
break;
}
System.out.println("Token:" + next);
}
}
}
Input
输入
1a;2b;3c;4d;5e;DONE;
Output
输出
Token:1a
Token:2b
Token:3c
Token:4d
Token:5e
Just be cautious while scanning decimal and signed numbers as scanning is LocaleDependent
扫描十进制和有符号数字时要小心，因为扫描是Locale相关的
回答by user5558192
You need to rather use method nextLine(). This methods prints entire line. By using next()it will print only one word in your sentence.
你需要使用 method nextLine()。此方法打印整行。使用next()它只会在你的句子中打印一个单词。
