How to have Password Regex?

Question

User969992919 posted

Hi,

I would like to ask how can I have a Regex for password to prevent space and to accept only numbers OR letters OR alphanumeric, minimum 6 and max of 20 characters?

Thanks,

Jassim

Answer 1

User-1171043462 posted

https://www.aspsnippets.com/Articles/Implement-Password-Policy-using-Regular-Expressions-and-ASPNet-RegularExpression-Validator.aspx

Refer

Answer 2

User-492460945 posted

Hi,

This link may help you.

• http://www.regexlib.com/Search.aspx?k=special+characters&c=0&m=0&ps=20&p=2

Thanks,

RajeshV.

Answer 3

User-369506445 posted

hi

please try below regex

"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)\S{6,20}$"

and example for web Form

<form runat="server">

        <asp:TextBox ID="textbox1" runat="server"></asp:TextBox><br />
        <asp:RegularExpressionValidator ID="Regex1" runat="server" ControlToValidate="textbox1"
            ValidationExpression="^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)\S{6,20}$"
            ErrorMessage="Minimum 6 Max 20 characters atleast 1 Alphabet, 1 Number and 1 Special Character and avoid space" ForeColor="Red" />
        <asp:Button runat="server" Text="validate" />

    </form>

for MVC

        [Required]
        [RegularExpression(@"^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)\S{6,20}$", ErrorMessage = "Invalid Password")]
        public int password { get; set; }

Answer 4

User-1171043462 posted

Regex

^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{6,20}$

ASP.Net Validator

<asp:TextBox ID="txtPolicy1" runat="server"></asp:TextBox><br />
<asp:RegularExpressionValidator ID="Regex1" runat="server" ControlToValidate="txtPolicy1"
    ValidationExpression="^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{6,20}$" ErrorMessage="Password must contain: Minimum 8 characters atleast 1 Alphabet and 1 Number" ForeColor="Red" />

Ref: Implement Password Policy using Regular Expressions and ASP.Net RegularExpression Validator

ASP.Net MVC

public class PersonModel
{
    [Display(Name = "Password")]
    [Required(ErrorMessage = "Password is required.")]
    [RegularExpression("^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{6,20}$", ErrorMessage = "Only Alphabets and Numbers allowed.")]
    public string UserName { get; set; }
}

Ref: RegularExpression Data Annotation example

Answer 5

User-330142929 posted

Hi Jrahma,

According to your description, I think we could use the following Regular Expression.

string pattern = @"^[a-zA-Z0-9]{6,20}$";

you could check whether the Regex match what you want by using the following code.

string pattern = @"^[a-zA-Z0-9]{6,20}$";
            string pattern1 = @"^(?=.*[A-Za-z])(?=.*\d)[A-Za-z\d]{6,20}$";
            //string pattern2 = @"^(?=.*[A-Za-z0-9])[A-Za-z\d]{6,20}$";
            Regex regex = new Regex(pattern); 
            string text = this.TextBox1.Text;
            var result = regex.IsMatch(text);
ClientScript.RegisterStartupScript(this.GetType(), "", "alert('"+result+"')", true);

Feel free to let me know if you have any questions

Best Regards

Abraham

Answer 6

User1204533129 posted

try this 

Best regards ,

kamal

/[^A-Za-z0-9]{6,30}+/g