Section 5.11 Assessment: While and For Loops
Subsection 5.11.1 Subgoals for Evaluating a Loop
Diagram which statements go together.
-
Define and initialize variables
Determine the start condition.
Determine the update condition.
Determine the termination condition.
Determine body that is repeated.
-
Trace the loop.
For every iteration of the loop, write down the values.
Exercises 5.11.2 Exercises
1.
0 2 1 0 2
0 2 0 2 0 2
0 2 1 0 2 1 0
0 2 0 2 0 2 0
0 1 2 1 2 1 2
Q1: What is printed as a result of executing the following code segment?
int k = 0;
while (k < 10) {
System.out.print((k % 3) + " ");
if ((k % 3) == 0)
k = k + 2;
else
k++;
}
2.
First: 15; Last: 27
First: 15; Last: 28
First: 16; Last: 27
First: 16; Last: 28
First: 16; Last: 29
Q2: What are the first and last numbers printed by the following code segment?
int number = 15;
while (number < 28) {
System.out.println(number);
number++;
}
3.
0
6
12
24
30
Q3: What is printed as a result of executing the following code segment?
int alpha = 24;
int beta = 30;
while (beta != 0) {
int rho = alpha % beta;
alpha = beta;
beta = rho;
}
System.out.println(alpha);
4.
Prints the value in num
Prints the sum of all the integers between 1 and num, inclusive
Prints the sum of all even integers between 1 and num, inclusive
Prints the sum of all odd integers between 1 and num, inclusive
Nothing is printed, it is an infinite loop
Q4: Considering the following code, which best describes what the code does?
int var = 0;
int num = 50;
for (int x = 1; x <= 50; x += 2) {
var = var + x;
}
System.out.println(var);
5.
5 20 5
5 20 10
5 25 5
5 25 10
30 25 10
Q5: What is printed as a result of executing the following code segment?
int typeA = 0;
int typeB = 0;
int typeC = 0;
for (int k = 1; k <= 50; k++) {
if (k % 2 == 0 && k % 5 == 0)
typeA++;
if (k % 2 == 0)
typeB++;
if (k % 5 == 0)
typeC++;
}
System.out.printf("%d %d %d", typeA, typeB, typeC);