Locating a digit within a string

Hi,
I'm trying to locate a single digit within a string containing multiple alphabetical characters. Is it possible to use the Character.isDigit method without having to define a single specific location within the string?
Alternatively can the indexOf method be used but specifying multiple search definitions instead of a single parameter?
I'm not supposed to use regular expressions either!
Cheers

for (int i=0;i<userName.length();i++)
{
if (!Character.isDigit(userName.charAt(i)))
{
validName=false;
System.out.println("Your User Name is Invalid.It must contain at least 1 digit!");
}
}

I tried using this. But instead of just checking whether it contains a digit, it actually prints a message for every character that is not
a digit. Where, as aforementioned, I only want it to print if there's no digit in the entire string!
Is there something I can insert into this piece of code to rectify this or am I barking up a tree that is in the wrong forest?

it has to look somethng like this:

Code:

---

validName = false;
start loop
check to see if string contains digit
if yes,
set variable validName = true
end loop
If validName == false
{ print name not valid }

---

Luck,
CJSL

for (int counter=0;counter<userName.length();counter++)
{
if (Character.isDigit(userName.charAt(counter))==true )
{
validName=true;
}
else
{
validName=false;
System.out.println("Your User Name is Invalid. It must contain at least one digit!");
}
}

I used this piece of code. My problem is that it prints the "user name is invalid" message for every character that isn't a digit, instead of printing it if the entire string doesn't contain at least one digit. Could somebody tell me where I'm going wrong with this one?

Sorry I just realised I more or less reposted the original question

... because you have the println in the loop. Please notice the pseudo code that I posted: the println is out of the loop.

Luck,
CJSL

thanks mate

Is it possible to do the same with punctuation symbols?
The user name being entered in my program must contain at least one punctuation symbol/mark.
The character class doesn't have isPunctuation like it has isDigit and isLetter.
How would i go about this?

you can check for the following functions though i am not very much sure.


static boolean isJavaIdentifierPart(char ch)
Determines if the specified character may be part of a Java identifier as other than the first character.
static boolean isJavaIdentifierStart(char ch)
Determines if the specified character is permissible as the first character in a Java identifier.

java.sun.com/j2se/1.4.2/docs/api/java/lang/Character.html