? 0-1 {0,1}
    + 大于1个 {1,}
    * {0,}

    1. <!DOCTYPE html>
    2. <html lang="en">
    3. <head>
    4.     <meta charset="UTF-8">
    5.     <meta name="viewport" content="width=device-width, initial-scale=1.0">
    6.     <title>Document</title>
    7. </head>
    8. <body>
    9.     <script>
    10.         /* 
    11.         ?    0-1     {0,1}
    12.         +    大于1个  {1,}
    13.         *  {0,}
    14.          */
    16.          var str = "hje1";
    17.          var reg =/\d+/
    18.          console.log(reg.test(str))
    19.     </script>
    20. </body>
    21. </html>