javascript - 如何使用以下字符串中的正则表达式来获取 url

Question

给定以下字符串，我可以使用什么正则表达式来仅提取 URL(我不需要引号)？

<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281438586869.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439101401.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439283119.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439479213.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281440090151.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281440244369.jpg\" /> \r\n</p>

Answer 1

您要查找的是/(\/.*?\.\w{3})/g:

var string = '<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281438586869.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439101401.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439283119.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439479213.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281440090151.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281440244369.jpg\" /> \r\n</p>';

console.log(string.match(/(\/.*?\.\w{3})/g));

分解:

• \/ 匹配正斜杠，用反斜杠转义
• .* 匹配 0 或更多非换行符
• \. 匹配一个点，用反斜杠转义
• \w{3} 恰好匹配三个“单词”字符(字母数字或下划线)
• g 标志表示正则表达式应匹配所有出现的地方

<强> .match 返回一个数组，您可以通过简单地指定索引或迭代循环来提取各个字符串(不带引号):

var string = '<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281438586869.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439101401.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439283119.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281439479213.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281440090151.jpg\" /> \r\n</p>\r\n<p>\r\n\t<img alt=\"\" src=\"/upload/201704/28/201704281440244369.jpg\" /> \r\n</p>';

var matches = string.match(/(\/.*?\.\w{3})/g);
for (var i = 0; i < matches.length; i++) {
  console.log(matches[i]);
}

希望这有帮助! :)