尝试
var elem = document.getElementById('testdiv');
elem.innerHTML = elem.innerHTML.replace( /(\d+)\.(\d+)/g, '$1.<span class="decimalPart">$2</span>' );
// (\d+) one or more digits
// \. a dot character. Must be escaped otherwise it means ANY character
// (\d+) one or more digits
// g regex flag to replace all instances, not just one.
decimalPart
然后在你的css中为类添加样式
.decimalPart {
width: 500px;
}
这具有将样式与 html 分开的额外优势。
更新
按照您的评论获取数字使用之前的角色
elem.innerHTML.replace( /(\s)([^\s\d]*?)(\d+)\.(\d+)/g, '$1<span class="currencySymbol">$2</span>$3.<span class="decimalPart">$4</span>' );
// (\s) space, tab, carriage return, new line, vertical tab, form feed
// ([\s\d]*?) any set of characters that are not a digit or the above zero or more times
// (\d+) one or more digits
// \. a dot character. Must be escaped otherwise it means ANY character
// (\d+) one or more digits
// g regex flag to replace all instances, not just one.
请注意,我已经考虑了占用多个字符的货币符号。