我想将大多数字符串转换为小写,除了括号内的那些字符.将括号外的所有内容转换为小写后,我想删除括号.因此,将{H} ell {o}世界作为输入应该将Hello world作为输出.删除括号很简单,但是有没有办法用正则表达式选择性地使括号小写之外的所有内容？如果没有简单的正则表达式解决方案,那么在javascript中最简单的方法是什么？
最佳答案
你可以试试这个：
var str='{H}ell{o} World';
str = str.replace(/{([^}]*)}|[^{]+/g,function (m,p1) {
return (p1)? p1 : m.toLowerCase();} );
console.log(str);
模式匹配：
{([^}]*)} # all that is between curly brackets
# and put the content in the capture group 1
| # OR
[^{]+ # anything until the regex engine meet a {
# since the character class is all characters but {
回调函数有两个参数：
完全匹配
p1第一个捕获组
如果p1不为空,则返回p1
否则整个匹配m是小写的.
细节：
"{H}" p1 contains H (first part of the alternation)
p1 is return as it. Note that since the curly brackets are
not captured,they are not in the result. -->"H"
"ell" (second part of the alternation) p1 is empty,the full match
is returned in lowercase -->"ell"
"{o}" (first part) -->"o"
" World" (second part) -->" world"
