1. Consider this: 
String name = "Alice"; 
name = name.toUpperCase(); 
System.out.println("Hello " + name +"!");
What's the output of it when embedded correctly in a complete program?

2. Now consider this: 

String name = "Alice"; 
/* name = */ name.toUpperCase(); 
System.out.println("Hello " + name +"!");
What's the output of it when embedded correctly in a complete program?

Consider this: 

String vehicle = "snowmobile";
3. What does vehicle + "vehicle" evaluate to?

4. What does vehicle.length() + "vehicle".length() evaluate to?

5. Please simplify the following expression (in which x is an int variable) 

(x > 3) && (x < 5)
That is, write a simpler, equivalent expression.

6-8. Same question for each of the following expressions 

(x > 3) || (x > 5)
(x > 3) || (x > 4)
(x > 3) && (x > 4)
9. Consider this (and that x and y are ints): 
if (x > 3) {
  if (x < 5)       
    y = 1; 
  else 
    if (x != 6) 
      y = 2;
    else 
      y = 3; 
} else 
    y = 4;
If y is 2 at the end, what value did x have in the beginning?

10. Now consider this: 

if (x > 3) {
  if (x > 5)       
    y = 1; 
  else 
    if (x != 6) 
      y = 2;
} else 
    y = 4;
If x is 6, what value does y have at the end?

11. Now we eliminate the curly braces altogether: 

if (x > 3) 
  if (x > 5)       
    y = 1; 
  else 
    if (x != 6) 
      y = 2;
else 
    y = 4;
If x is 6, what value does y have at the end?

12. What's the value of 

(1 + 2 + 3 + "4").length()
13. What's the value of 
Integer.parseInt(a.substring(0, 1))
where a is the string "345"?

14. What's the value of 

a.charAt(0) - a.charAt(2)
where a is the string "345"?

15. What's the value of 

a.charAt(0) - '0'
where a is the string "345"?

16. Consider this: 

int x = 0; 
while (x > 0) {
  x += 1; 
}
Is it an infinite loop?

17. Consider this: 

int x = 0; 
do { 
  x += 1; 
} while (x > 0);
Is it an infinite loop?

18. What's the output of this program when compiled and run: 

class One {
    int n = 3; 
    One() {
	this(7); 
    }
    One(int n) {
	this.n = n; 
    }
    public static void main(String[] args) {
	One a = new One(9); 
	One b = new One(); 
	System.out.println(a.n + b.n); 
    }
}
19. Consider this: 
public class Two {
    public static void main(String[] args) {
	System.out.print(fun(1) + " ");
    }
    public static int fun(int x) {
	System.out.print(x + " ");
	return x + 1;
    }
}
What does it print?

20. Consider this: 

public class Three {
    public static void main(String[] args) {
	int x = 2;
	System.out.print(fun(x) + " ");
	System.out.print(x + " ");
    }
    public static int fun(int x) {
	x = x - 1;
	return x;
    }
}
What does it print?

21. Consider this: 

public class Five {
    public static void main(String[] args) {
	boolean yo = "yo".equals("yo"); 
	System.out.println(yo(yo));
    }
    public static boolean yo (boolean yo) {
	return yo && (! yo); 
    }
}
What does it print?

22. What does this program print? 

class Six { 
    public static String mix(String s, String t) {
	String ans = "";
	int slen = s.length();
	int tlen = t.length();
	for (int i = 0; i < slen && i < tlen; i++) {
	    ans = t.charAt(i) + s.charAt(i) + ans;
	}
	return ans;
    }
    public static void main(String[] args) {
	System.out.println(Six.mix("mix", "six")); 
    }
}

23. Now suppose we change one line in mix as follows: 

class Six { 
    public static String mix(String s, String t) {
	String ans = "";
	int slen = s.length();
	int tlen = t.length();
	for (int i = 0; i < slen && i < tlen; i++) {
	    ans = ans + t.charAt(i) + s.charAt(i); 
	}
	return ans;
    }
    public static void main(String[] args) {
	System.out.println(Six.mix("mix", "six")); 
    }
}
Now, what does it print?

24. And suppose we change that line one more time: 

class Six { 
    public static String mix(String s, String t) {
	String ans = "";
	int slen = s.length();
	int tlen = t.length();
	for (int i = 0; i < slen && i < tlen; i++) {
	    ans = t.charAt(i) + ans + s.charAt(i);
	}
	return ans;
    }
    public static void main(String[] args) {
	System.out.println(Six.mix("mix", "six")); 
    }
}
Now, what does it print?

25. And we change it one more time: 

class Six { 
    public static String mix(String s, String t) {
	String ans = "";
	int slen = s.length();
	int tlen = t.length();
	for (int i = 0; i < slen && i < tlen; i++) {
	    ans = s.charAt(i) + ans + t.charAt(i);
	}
	return ans;
    }
    public static void main(String[] args) {
	System.out.println(Six.mix("mix", "six")); 
    }
}

26. What's the output of this program when compiled and run? 

public class Seven {
    public static void main(String[] args) {
	System.out.println(fun(1, fun(fun(2, fun(3, 4)), 5)));
    }
    public static int fun(int a, int b) {
	return b - a;
    }
}

27. What does this evaluate to: 

a[a[a[a[0]]]]
if a is defined as follows: int[] a = {5, 4, 0, 1, 3, 2}; ?

28. Same question about a[a[a[a[2]]]].

29. Same question about a[1 + a[1 + a[1 + a[2]]]].

Consider the following definition: 

int[][] a = { { 1, 2, 3, 4}, { 5, 6, 7, 8}, { 9, 1, 2, 3} };
30. What does System.out.println(a[0][1] + a[1][0]); produce?

31. What does System.out.println(a.length); produce?

32. What does System.out.println(a[0].length); produce?