Question

我需要一些帮助才能有效地完成某些逻辑。我需要删除此字符串末尾的所有break标记和换行符，然后在完成所有字符串操作后将它们添加回字符串。

str = "<br><br>My test string is here and <br> has some text in it.<br><br><br>\n\n<br>\n<br>";

// Code here that pops off all the break tags.

new_str = "<br><br>My test string is here and <br> has some text in it.";

// Break tags stored in a variable maybe?
end_tags = '<br><br><br>\n\n<br>\n<br>';

// More manipulation of the string.
final_str = "<br><br>My test string is here and <br> has..." + end_tags;

我知道这可以在正则表达式中优雅地完成，我只是碰壁，使其工作得足够快。

Answer 1

您可以简单地使用正则表达式来解决您的问题：

// Match all <br> and \n tags in the end
const matches = str.match(/^(.+?)((?:\<br\>|\n)+)$/)

// Matches = [Entire String, Stuff before the ending, all the end <br>s]
const [_, new_str, end_tags] = matches

ES2015 Way

// Match all <br> and \n tags in the end
var matches = str.match(/^(.+?)((?:\<br\>|\n)+)$/)

// Matches = [Entire String, Stuff before the ending, all the end <br>s]
var new_str = matches[1], end_tags = matches[2]

Answer 2

使用正则表达式在replace上调用str方法，以便在最后进行匹配：

＆＃13;

str = "<br><br>My test string is here and <br> has some text in it.<br>\n\n<br><br>";

new_str = str.replace(/(?:<br>|[\n\r])*$/, function(match) {
    end_tags = match;
    return '';
});

console.log(end_tags);

＆＃13;

Answer 3

编辑：这是我实现这个

的方式

var str = "<br><br>My test string is here and <br> has some text in it.<br><br><br>\n\n<br>\n<br>";

// replace line breaks with <span> to make things easier

var replaceStr = str.replace(/(\r\n|\r|\n)/g, '<span>');

// this get's the last line breaks or new lines at the end of the 
// string but also one extra string at the begining
// i.e it gets .<br><br><br>\n\n<br>\n<br> notice the (.) in front
var pattern = /(([^<br])(<br>|<span>)<br>.+|<span>.+|$).+$/gm;

var found = replaceStr.replace(pattern, function(match) {
  var firstChar = match.charAt(0);
  var remainder = match.substring(1);

  // add hello to remainder string

  return firstChar + ' add text, do stuff here ' + remainder;

});

// replace all spans to new line back

var finalResult = found.replace(/(<span>)/g, '\n');

删除并重新添加HTML标记末尾的br标记

3 个答案:

ES2015 Way