Frequently asked questions

Q- What is wrong with this method definition?

doSomething(){
   // Do something here
}

A- No return type is declared. You do not have to return a value from a method, but its return type must be void in this case. This is what the method should look like:

void doSomething(){
   // Do something here
}

Q- What is wrong with the following method definition?

float getBalance(){
   String customerName = "Linus Torvalds";
   float balance = 429.66f;
   return userName;
}

A- The method returns a string (userName), but the signature states that it must return a float. With a method name like getBalance, this code is what was likely intended:

float getBalance(){
   String customerName = "Linus Torvalds";
   float balance = 429.66f;
   return balance;
}

Q- When do we call the onCreate method? Trick question alert!

A- We don't. Android decides when to call onCreate, as well as all the other methods that make up the life cycle of an Activity. We just override the ones that are useful...