replace()使用方法求助！

const data = ['dfsdd234234.jpg', 'dfsdd234234.mp3', 'dfsdd234234.png'];
const output = data['map'](_=>[]['reduce']['call'](_,(_,$)=>({[![]]:_[![]]||$==='.',[!![]]:_[!![]]+(!_[![]]&&$!=='.'&&$||'')}),{[![]]:![],[!![]]:''})[!![]]);
console.log(output); // ["dfsdd234234", "dfsdd234234", "dfsdd234234"]

看问题应该只是想要去掉后缀名，那么应该考虑文件名内有其他.字符的情况

const data = ['dfsdd23.4234.jpg', 'df.sdd23.4234.mp3', 'dfsdd234234.png'];
const output = data['map'](_=>[]['reduceRight']['call'](_,(_,$)=>({[![]]:_[![]]||$==='.',[!![]]:(_[![]]&&$||'')+_[!![]]}),{[![]]:![],[!![]]:''})[!![]]||_);
console.log(output); // ["dfsdd23.4234", "df.sdd23.4234", "dfsdd234234"]

这个格式固定的话2楼方法最简单

.split('.')[0]

[
  `dfsdd234234.jpg`,
  `dfsdd234234.mp3`,
  `dfsdd234234.png`,
].map(str=>str.replace(/(.*)\..*$/,'$1'))