**question:** Javascript regular expression password validation having special characters url:http://stackoverflow.com/questions/12090077/javascript-regular-expression-password-validation-having-special-characters ``` var reg = /^(?=.*[0-9])(?=.*[!@#$%^&*])[a-zA-Z0-9!@#$%^&*]{6,16}$/; ``` > 说明 必须拥有数字和特殊字符，并且在6~16位之间 Without it, your current regex only matches that you have 6 to 16 valid characters, it doesn't validate that it has at least a number, and at least a special character. That's what the lookahead above is for. `(?=.*[0-9])` - Assert a string has at least one number; `(?=.*[!@#$%^&*])` - Assert a string has at least one special character. > 学习 密码需求：必须满足大写字母，数字，特殊字符中两个条件。长度8~16