通过 js正则表达式 获取字符串 svg xmlns=httpwwww3org2000svg width=11893ex height=2072ex role=img focusable=false viewBox=0 -8339 52567 9159 xmlnsxlink=httpwwww3org1999xlink aria-hidden=true style=vertical-align -0

你可以使用以下正则表达式来获取字符串中use的xlink:href的内容并去掉#号：

var str = '<svg xmlns="http://www.w3.org/2000/svg" width="11.893ex" height="2.072ex" role="img" focusable="false" viewBox="0 -833.9 5256.7 915.9" xmlns:xlink="http://www.w3.org/1999/xlink" aria-hidden="true" style="vertical-align: -0.186ex;"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><use data-c="1D44E" xlink:href="#MJX-TEX-I-1D44E"></use></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><use data-c="32" xlink:href="#MJX-TEX-N-32"></use></g></g><g data-mml-node="mo" transform="translate(1187.8,0)"><use data-c="2B" xlink:href="#MJX-TEX-N-2B"></use></g><g data-mml-node="msup" transform="translate(2188,0)"><g data-mml-node="mi"><use data-c="1D44F" xlink:href="#MJX-TEX-I-1D44F"></use></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><use data-c="32" xlink:href="#MJX-TEX-N-32"></use></g></g><g data-mml-node="mo" transform="translate(3331.3,0)"><use data-c="3D" xlink:href="#MJX-TEX-N-3D"></use></g><g data-mml-node="msup" transform="translate(4387.1,0)"><g data-mml-node="mi"><use data-c="1D450" xlink:href="#MJX-TEX-I-1D450"></use></g><g data-mml-node="mn" transform="translate(466,363) scale(0.707)"><use data-c="32" xlink:href="#MJX-TEX-N-32"></use></g></g></g></g></svg>';

var regex = /xlink:href="#([^"]*)"/g;
var matches = str.match(regex);

var result = [];
for (var i = 0; i < matches.length; i++) {
  var match = matches[i];
  var href = match.replace('xlink:href="#', '').replace('"', '');
  result.push(href);
}

console.log(result);

这将输出一个数组，其中包含所有use标签的xlink:href的内容（去掉#号）：

[
  'MJX-TEX-I-1D44E',
  'MJX-TEX-N-32',
  'MJX-TEX-N-2B',
  'MJX-TEX-I-1D44F',
  'MJX-TEX-N-32',
  'MJX-TEX-N-3D',
  'MJX-TEX-I-1D450',
  'MJX-TEX-N-32'
]