java 将填充空格插入字符串
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Insert padding whitespace into string
提问by Johannes Charra
Pretty basic problem, but difficult to get into an acceptable form:
相当基本的问题，但很难达到可接受的形式：
I want to transform a string by inserting a padding every 3 whitespaces like
我想通过每 3 个空格插入一个填充来转换字符串，例如
"123456789" -> "123 456 789"
“123456789”->“123 456 789”
"abcdefgh" -> "abc def gh"
"abcdefgh" -> "abc def gh"
My code currently is
我的代码目前是
public String toSpaceSeparatedString(String s) {
if (s == null || s.length() < 3) {
return s;
}
StringBuilder builder = new StringBuilder();
int i;
for (i = 0; i < s.length()-3; i += 3) {
builder.append(s.substring(i, i+3));
builder.append(" ");
}
builder.append(s.substring(i, s.length()));
return builder.toString();
}
Can anyone provide a more elegant solution?
谁能提供更优雅的解决方案？
回答by wjans
You can do this using a regular expression:
您可以使用正则表达式执行此操作：
"abcdefgh".replaceAll(".{3}", " builder.append(String.format("%4s", threeDigitString));
")
回答by dcn
You can use printfor String.formatlike so:
您可以使用printf或String.format喜欢这样：
"abcdef gh".replaceAll("\s*(..[^ ])\s*", " "); // --> "abc def gh"
More information on formatted output/strings in the API.
有关API 中格式化输出/字符串的更多信息。
回答by Bohemian
This doesn't put a space if there's already one there:
如果已经有一个空间，这不会放置一个空间：
##代码##回答by naveinaustin
The replaceAlllooks to be the best, but if you consider a number like 12345 it would be converted to 123 45. But in numbers I believe it should be 12 345
在replaceAll看起来是最好的，但如果你考虑一些像12345将它转换为123 45.但数字我相信它应该是12 345
