How to check a string starts with numeric number?

Question

I have a string which contains alphanumeric character.

I need to check whether the string is started with number.

Thanks,

Answer 1

Sorry I didn't see your Java tag, was reading question only. I'll leave my other answers here anyway since I've typed them out.

Java

String myString = "9Hello World!";
if ( Character.isDigit(myString.charAt(0)) )
{
    System.out.println("String begins with a digit");
}

C++:

string myString = "2Hello World!";

if (isdigit( myString[0]) )
{
    printf("String begins with a digit");
}

Regular expression:

\b[0-9]

Some proof my regex works: Unless my test data is wrong?