I have a problem with replacing last word in JS, I am still searching solution but i cannot get it.
I have this code:
var string = $(element).html(); // "abc def abc xyz"
var word = "abc";
var newWord = "test";
var newV = string.replace(new RegExp(word,'m'), newWord);
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?
Here is an idea ....
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
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)
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
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.
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
Good luck :)
// create array
var words = $(element).html().split(" ");
// find last word and replace it
words[words.lastIndexOf("abc")] = newWord
// put it back together
words = words.join(" ");
You can use lookahead to get last word in a sentence:
var string = "abc def abc xyz";
var repl = string.replace(/\babc\b(?!.*?\babc\b)/, "test");
//=> "abc def test xyz"
You want to both:
abcabc afterward in the stringSo you can use:
abc(?!.*abc)
(?!...) is a negative lookahead, it will fail the whole regex match if what's inside the lookahead is matched.
Also be careful as this would match abc in abcdaire: if you only want abc as a separate word you need to add word boundaries \b:
\babc\b(?!.*\babc\b)
string.replace(/\babc\b(?!.*\babc\b)/, '') replaces the last abc with a space, do you know why? jsfiddle.net/5q9K8/11
I'm not too familiar with JavaScript but you can probably twist this to fit your needs:
(\b\w+\b)(.*)(\1) replace with \1\2+'your_key_word'
See the demo to see what I mean.
try
var string = $(element).html(); // "abc def abc xyz"
var word = "abc";
var newWord = "test";
var newV = string.replace(new RegExp(word+'$'), newWord);
You can use the fact that the replace method replaces only the first occurrence of the target string if used without the global flag, and try something like:
"abc def abc xyz abc jkl".split(' ').reverse().join(' ').replace('abc', 'test').split(' ').reverse().join(' ')
