### 连号的备选字符集 [0-9]一位数字 [a-z]一位小写字母 [A-Z]一位大写字母 [0-9a-zA-Z]一位数字或字母 ~~~ <script> var reg = /[0-9]/g; var reg01 = /[a-zA-Z]/g; var reg02 = /[0-9a-zA-Z]/g; var str = "helloJKLDJSFJL321313219767和"; console.log(str.replace(reg,"*")); console.log(str.replace(reg01,"*")); console.log(str.replace(reg02,"*")); </script> ~~~