How to check if string contains any digit

How to check if string contains any digit

How do I check if a string contains a any digit/ number?
this is the code I cant seem to get working 

  3. Str = "1Mustard Mustard23";
  4. if (Str.contains("[0-9]"))
  5. {
  6. info true ;
  7. }
  8. else 
  9.     {
  10. info false ;
  11.     }