正则表达式不起作用

Question

尝试用连字符替换任何非字母数字字符.看不出为什么它不应该工作.它返回原始字符串不变.

item.mimetype = "image/png";

var mimetype = item.mimetype.toLowerCase().replace("/[^a-z0-9]/g",'-');

Answer 1

删除正则表达式周围的引号.

如上所述,Javascript正在寻找字符串 "/[^a-z0-9]/g"

// This works
"image/png".toLowerCase().replace(/[^a-z0-9]/g,'-'); 

// And if writing unquoted regular expressions makes you feel icky:
"image/png".toLowerCase().replace(new RegExp("[^a-z0-9]", "g"), '-');

// And if I might do a full rewrite:
"image/png".toLowerCase().replace(/\W/g, '-');

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