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Key to CSE142 Sample Midterm, Spring 2022 handout #10
1. Expression Value
-----------------------------------------------
3 * (5 - 2) - 3 - 2 * 2 2
4 * 7 % 8 + 132 % 10 + 3 % 4 9
27 / 5 / 2 + 3.4 * 2 - 1.1 * 2 6.6
9 + 9 + "9 + 9" + 9 + 9 "189 + 999"
19 / 2 / 2.0 + 2.5 * 6 / 2 + 0.5 * 4 14.0
2. Parameter Mystery. The program produces the following output.
a snow and slippery for sleet
a storm and snow for sleetsnow
a snowsleet and sleetsnow for snowstorm
a sun and storm for sunny
3. Method Call Output Produced
---------------------------------------
ifElseMystery(2, 2); 4 2
ifElseMystery(3, 1); 1 4
ifElseMystery(4, 0); 4 1
ifElseMystery(5, 3); 4 7
ifElseMystery(1, 2); 2 0
ifElseMystery(7, 4); 8 7
4. Method Call Output Produced
---------------------------------------
mystery(8); 1 8
mystery(32); 2 5
mystery(184); 3 13
mystery(8239); 4 22
5. x == 1 x % 2 == 1 y == 0
+---------------------+---------------------+---------------------+
Point A | sometimes | sometimes | always |
+---------------------+---------------------+---------------------+
Point B | never | sometimes | sometimes |
+---------------------+---------------------+---------------------+
Point C | sometimes | sometimes | never |
+---------------------+---------------------+---------------------+
Point D | never | never | sometimes |
+---------------------+---------------------+---------------------+
Point E | always | always | sometimes |
+---------------------+---------------------+---------------------+
6. One possible solution appears below.
public static int generate(Scanner console) {
System.out.print("number between -5 and 5? ");
int target = console.nextInt();
Random r = new Random();
int next = r.nextInt(11) - 5;
System.out.print("numbers are: " + next);
int count = 1;
while (next != target) {
next = r.nextInt(11) - 5;
System.out.print(", " + next);
count++;
}
System.out.println();
System.out.println("came up after " + count + " tries");
return count;
}
7. One possible solution appears below.
public static int digitRange(int n) {
int min = n % 10;
int max = n % 10;
while (n > 0) {
int digit = n % 10;
n = n / 10;
if (digit < min) {
min = digit;
}
if (digit > max) {
max = digit;
}
}
return max - min;
}
8. Two possible solutions appear below.
public static void printStripped(String s) {
boolean inComment = false;
for (int i = 0; i < s.length(); i++) {
char next = s.charAt(i);
if (next == '<') {
inComment = true;
} else if (inComment && next == '>') {
inComment = false;
} else if (!inComment) {
System.out.print(next);
}
}
System.out.println();
}
public static void printStripped(String s) {
int start = s.indexOf('<');
while (start != -1) {
int stop = s.indexOf('>', start + 1);
s = s.substring(0, start) + s.substring(stop + 1);
start = s.indexOf('<');
}
System.out.println(s);
}
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