<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <script> var age = "x18"; var reg = /^\d{1,3}$/; var b = reg.test(age); if(b == true) { console.log("正确"); }else { console.log("错误"); } </script> <body> </body> </html>
