Java gives you the ability to dynamically create strings. Even after you set the string value, you can add more characters to the string value throughout the code. This process lets you build a string ...

A class whose objects wrap themselves around primitive type variables for storing those variables in a data structure object that only stores objects—not variables. Character is an example. These tips ...

A regex of the form [:alpha:]{2}\d{3} should do the trick. If your regex engine doesn't support [:alpha:], use [a-zA-Z] instead.