比较粗暴 let str = readline(); let a = str.replace(/[^a-zA-Z]+/g, ''); let b = str.replace(/[^\s]+/g, ''); let c = str.replace(/[^0-9]+/g, ''); let d = str.replace(/[a-zA-Z0-9\s]+/g, ''); console.log(a.length); console.log(b.length); console.log(c.length); console.log(d.length);