Chapter 3

Q1) What does this code do?

// setContentView(R.layout.activity_main);

A) Nothing, because it is commented out with //.

Q2) Which of these lines causes an error?

String a = "Hello";
String b = " Vinton Cerf";
int c = 55;
a = a + b
c = c + c + 10;
a = a + c;
c = c + a;

A) The fourth line, a = a + b, has no semicolon, so it will cause an error. The last line, c = c + a;, will also cause an error because you cannot assign a string to an int value.

Q3) We talked a lot about operators and how different operators can be used together to build complicated expressions. Expressions, at a glance, can sometimes make code look complicated. However, when looked at closely, they are not as tough as they seem. Usually, it is just a case of splitting the expressions into smaller pieces to work out what is going on. Here is an expression that is more convoluted than anything else you will ever meet in this book. As a challenge, can you work out what x will be?

int x = 10;
int y =...