我认为减少正则表达式的数量很难,因为有时您只需要换行符,有时您也需要一个制表符。有时您需要写回一个字符,有时是两个字符。但这里有一个使 CSS 看起来相当不错的替换列表:
str.replace(/\{/g, " {\n\t")        // Line-break and tab after opening {
   .replace(/;([^}])/g, ";\n\t$1")  // Line-break and tab after every ; except
                                    // for the last one
   .replace(/;\}/g, ";\n}\n\n")     // Line-break only after the last ; then two
                                    // line-breaks after the }
   .replace(/([^\n])\}/g, "$1;\n}") // Line-break before and two after } that
                                    // have not been affected yet
   .replace(/,/g, ",\n")            // line break after comma
   .trim()                          // remove leading and trailing whitespace
使这个:
 str = 'body{margin:0;padding:0}section,article,.class{font-size:2em;}'
看起来像这样:
body {
    margin:0;
    padding:0;
}
section,
article,
.class {
    font-size:2em;
}
如果您不关心那些省略的分号被放回原处,您可以通过更改顺序来缩短它:
str.replace(/\{/g, " {\n\t")
   .replace(/\}/g, "\n}\n\n")    // 1 \n before and 2 \n after each }
   .replace(/;(?!\n)/g, ";\n\t") // \n\t after each ; that was not affected
   .replace(/,/g, ",\n")
   .trim()