java - Custom Unchecked Exceptions -

okay guys i've been trying figure out past day or so. homework assignment has me creating both unchecked , checked exceptions. checked exceptions believe must handled before compiling (with try & catch or throwing next thing calls it. unchecked exceptions don't understand how custom ones work. caught @ runtime , don't need thrown or encased try & catch if they're custom how ide or whatever know for? example: 1 of custom unchecked files supposed trigger if user adds pokemon party full, how tell ide that's needs happen? exception file looks like:

public class partyisfullexception extends runtimeexception {      public partyisfullexception() {         super();     }      public partyisfullexception(string message) {         super(message);     } } 

and want implement in method, idk how it. realize can't throw them because user won't expecting them , therefore won't try catch them.

public void addtoparty(string name) throws partyisfullexception {         boolean exists = false;         (int = 0; < 152; i++) {             exists = (name.equals(pokedex[i]));         }         if (exists) {             throw new pokemonalreadyexistsexception();         } else {             if (partypos < 6) {             party[partypos] = name;             partypos++;             } else {                 throw new partyisfullexception();             }         }     } 

i realize can't throw them because user won't expecting them , therefore won't try catch them.

you can throw them!

in real project, should documented.

/*  * @throws partyisfullexception if ispartyfull() return true  */ public void addtoparty(string name) throws partyisfullexception {...} 

usually unchecked exception used situation client of method avoiding exceptional condition e.g.:

if(theparty.ispartyfull()) {     // tell user party full     // , can't add more pokemon } else {     theparty.addtoparty(thepokemon); } 

and shouldn't have explicitly catch because handling circumstance.

if exception thrown , there not try-catch outside, throw way terminate thread. (for small program main, means program crashes.)