在javascript中替换最后出现的单词 [英] Replace last occurrence word in javascript

问题描述

我在替换JS中的最后一个单词时遇到问题，我仍在搜索解决方案，但我无法得到它。

I have a problem with replacing last word in JS, I am still searching solution but i cannot get it.

我有这段代码：

var string = $(element).html(); // "abc def abc xyz"
var word   = "abc";
var newWord = "test";

var newV   = string.replace(new RegExp(word,'m'), newWord);

我想在此字符串中替换最后一个单词abc，但现在我只能替换所有或第一个在字符串中出现。我怎样才能做到这一点？也许不是好方法？

I want replace last word "abc" in this string, but now I can only replace all or first occurrence in string. How can I do this? Maybe is not good way?

推荐答案

这是一个想法....

Here is an idea ....

这是一个区分大小写的字符串搜索版本

This is a case-sensitive string search version

var str = 'abc def abc xyz';
var word = 'abc';
var newWord = 'test';

// find the index of last time word was used
// please note lastIndexOf() is case sensitive
var n = str.lastIndexOf(word);

// slice the string in 2, one from the start to the lastIndexOf
// and then replace the word in the rest
str = str.slice(0, n) + str.slice(n).replace(word, newWord);
// result abc def test xyz

如果你想要一个不区分大小写的版本，那么代码必须改变。让我知道，我可以为你改变它。 （PS。我这样做，所以我会很快发布）

If you want a case-insensitive version, then the code has to be altered. Let me know and I can alter it for you. (PS. I am doing it so I will post it shortly)

更新：这是一个不区分大小写的字符串搜索版本

Update: Here is a case-insensitive string search version

var str = 'abc def AbC xyz';
var word = 'abc';
var newWord = 'test';

// find the index of last time word was used
var n = str.toLowerCase().lastIndexOf(word.toLowerCase());

// slice the string in 2, one from the start to the lastIndexOf
// and then replace the word in the rest
var pat = new RegExp(word, 'i')
str = str.slice(0, n) + str.slice(n).replace(pat, newWord);
// result abc def test xyz

NB 以上代码寻找一个字符串。不是整个单词（即RegEx中的单词边界）。如果字符串必须是一个完整的单词，那么它必须重做。

N.B. Above codes looks for a string. not whole word (ie with word boundaries in RegEx). If the string has to be a whole word, then it has to be reworked.

更新2：这是一个不区分大小写的整个单词与RegEx匹配版本

Update 2: Here is a case-insensitive whole word match version with RegEx

var str = 'abc def AbC abcde xyz';
var word = 'abc';
var newWord = 'test';

var pat = new RegExp('(\\b' + word + '\\b)(?!.*\\b\\1\\b)', 'i');
str = str.replace(pat, newWord);
// result abc def test abcde xyz

祝你好运
：）

Good luck :)

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