java 如何替换字符串中的最后一个单词
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How to replace the last word in a string
提问by Bitmap
Does anyone knows how to replace the last word in a String.
有谁知道如何替换字符串中的最后一个单词。
Currently I am doing:
目前我正在做：
someStr = someStr.replace(someStr.substring(someStr.lastIndexOf(" ") + 1), "New Word");
The above code replaces every single occurance of the word in the string.
上面的代码替换字符串中出现的每个单词。
Thanks.
谢谢。
回答by aioobe
You could create a new string "from scratch" like this:
您可以像这样“从头开始”创建一个新字符串：
someStr = someStr.substring(0, someStr.lastIndexOf(" ")) + " New Word";
Another option (if you really want to use "replace" :) is to do
另一种选择（如果你真的想使用“替换”:) 是做
someStr = someStr.replaceAll(" \S*$", " New Word");
replaceAlluses regular expressions and \S*$means a space, followed by some non-space characters, followed by end of string. (That is, replace the characters after the last space.)
replaceAll使用正则表达式并\S*$表示一个空格，后跟一些非空格字符，后跟字符串结尾。（即，替换最后一个空格后的字符。）
回答by JB Nizet
You're not far from the solution. Just keep the original string until the last index of " ", and append the new word to this substring. No need for replacehere.
你离解决方案不远了。只需保留原始字符串直到 的最后一个索引" "，并将新单词附加到此子字符串。replace这里不需要。
回答by Waldo Bronchart
What your code is doing is replacing the substring by "New word".
您的代码正在做的是用“新词”替换子字符串。
Instead you need to substring first, and then do a replace on that string.
相反，您需要先进行子字符串化，然后对该字符串进行替换。
Here's how I would do it
这是我将如何做到的
someStr = someStr.substring(0, someStr.lastIndexOf(" ") + 1) + "New word"
回答by SBerg413
try:
尝试：
someStr = someStr.substring( someStr.lastIndexOf(" ") ) + " " + new_word;
回答by AlexR
use this: someStr.substring(0, someStr.lastIndexOf(" ")) + "New Word".
使用这个：someStr。substring(0, someStr.lastIndexOf(" ")) + "New Word".
You can also use regular expression, e.g. someStr.repalaceFirst("\s+\S+$", " " + "New Word")
你也可以使用正则表达式，例如 someStr.repalaceFirst("\s+\S+$", " " + "New Word")
回答by Muhammad Gelbana
Try this regex (^.+)b(.+$)
试试这个正则表达式 (^.+)b(.+$)
Example (Replace the last bcharacter)
示例（替换最后一个b字符）
System.out.println("1abchhhabcjjjabc".replaceFirst("(^.+)b(.+$)", ""));
