Java 编写一个程序，允许用户输入一个字符串，然后打印出以逗号分隔的字符串的字母
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2755012/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Write a program that allows the user to enter a string and then prints the letters of the String separated by comma
提问by WM.
The output is always a String, for example H,E,L,L,O,. How could I limit the commas? I want the commas only between letters, for example H,E,L,L,O.
输出始终是一个字符串，例如H,E,L,L,O,。我怎么能限制逗号？我只想要字母之间的逗号，例如H,E,L,L,O.
import java.util.Scanner;
import java.lang.String;
public class forLoop
{
public static void main(String[] args)
{
Scanner Scan = new Scanner(System.in);
System.out.print("Enter a string: ");
String Str1 = Scan.next();
String newString="";
String Str2 ="";
for (int i=0; i < Str1.length(); i++)
{
newString = Str1.charAt(i) + ",";
Str2 = Str2 + newString;
}
System.out.print(Str2);
}
}
采纳答案by mihsathe
The easiest way I see is :
我看到的最简单的方法是：
public static void main(String[] args) {
Scanner Scan = new Scanner(System.in);
System.out.print("Enter a string: ");
String Str1 = Scan.nextLine();
String newString="";
String Str2 ="";
for (int i=0; i < Str1.length()-1; i++)
{
newString = Str1.charAt(i) + ",";
Str2 = Str2 + newString;
}
Str2 = Str2 + Str1.charAt(Str1.length()-1);
System.out.println(Str2);
}
The output it will give is :
它会给出的输出是：
run:
Enter a string: Hello world
H,e,l,l,o, ,w,o,r,l,d
BUILD SUCCESSFUL (total time: 5 seconds)
Though I will highly recommend learning regular expression as suggested by @Roman. Till then this will do the trick. :)
尽管我强烈建议您按照@Roman 的建议学习正则表达式。到那时，这将奏效。:)
回答by Woot4Moo
Since this is homework I'll help you out a little without giving the answer:
由于这是家庭作业，我会在不给出答案的情况下帮助您：
If you want the output to only be inbetween letters IE: A,B,C instead of A,B,C, which is what I imagine you are asking about. Then you need to look at your for loop and check the boundary conditions.
如果您希望输出仅在字母 IE 之间：A、B、C 而不是 A、B、C，这就是我想您要问的。然后您需要查看您的 for 循环并检查边界条件。
回答by BalusC
Just don't append the comma when the lastitem of the loop is to be appended. You have the item index by iand the string length by Str2.length(). Just do the primary school math with a lesser-than or a greater-than operator in an ifstatement.
当要附加循环的最后一项时，不要附加逗号。您有项目索引 byi和字符串长度 by Str2.length()。只需在if语句中使用小于或大于运算符进行小学数学计算即可。
回答by Roman
Try regular expressions:
试试正则表达式：
String input = scanner.next();
String output = input.replaceAll(".", "output = output.substring (0, ouput.length() - 2);
,");
With spaces it would be a bit easier since you don't need to abandon last 'odd' comma:
使用空格会更容易一些，因为您不需要放弃最后一个“奇数”逗号：
System.out.println(Arrays.toString("HELLO".toCharArray()).replaceAll("[\[ \]]", ""));
回答by aioobe
When you've figured out the loop-solution, you could try the following ;)
找出循环解决方案后，您可以尝试以下操作；)
String s = "HELLO";
StringBuilder sb = new StringBuilder();
for (int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
if (i == 0) { // first
sb.append("(" + ch + ")");
} else if (i == s.length() - 1) { // last
sb.append("<" + ch + ">");
} else { // everything in between
sb.append(Character.toLowerCase(ch));
}
}
System.out.println(sb.toString());
// prints "(H)ell<O>"
回答by polygenelubricants
The following snippet should be instructive. It shows:
以下代码段应该具有指导意义。表明：
- How to use
StringBuilderfor building strings - How to process each
charin aStringusing an explicit index- How to detect if it's the first/last iteration for special processing
- 如何使用
StringBuilder构建字符串 - 如何处理每
char一个String使用一个明确的指标- 如何检测它是否是特殊处理的第一次/最后一次迭代
##代码##
