Progress Checks: Chapter 6
1. Identify the invalid if statements
a. if (a < b) then
x=y;
else
x=z;
b. if (a < b)
else x=
y;
c. if (a < b)
x= y;
else {
x= z;
};
d. if (a < b) {
x= y; }
else
x= z;
2. Express the following if-then statements using
if-then-else.
a. if (a < b) x= y;
b. if (a < b) {}
c. if (a < b) x= y;
if (a >= b)
x=z;
3. Using a message box, create if-else statements that
sets no car crashes to print a "Safe Driver," at least one crash
"Insurance increases" and if the number of car crashes is less than 0
"Prevention."
4. Indent the following if statements properly.
a. if (a==b) if (c==d) a=1; else b=1; else c=1;
b. if (a == b) a = 1; if (c == d) b = 1; else c = 1;
c. if (a == b) {if (c == d) a = 1; b = 2; } else b = 1;
d. if (a == b) {
if (c ==
d) a = 1; b = 2; }
else {b
= 1; if (a == d) d = 3;
else c =
1;}
5. Which two of the following three if statements are
equivalent?
a. if (a == b)
if (c ==
d) a = 1;
else b =
1;
b. if (a == b) {
if (c ==
d) a = 1; }
else b =
1;
c. if (a == b)
if (c ==
d) a = 1;
else b =
1;
6. Evaluate the following boolean expressions. For each
of the following ex-pressions,
assume x is 10, y is 20, and z is 30. Indicate which of
the fol-lowing
boolean expressions are always true and which are always
false,
regardless of the values for x, y, or z.
a. x < 10 || x > 10
b. x > y && y > x
c. (x < y + z) && (x + 10 <= 20)
d. z - y == x && Math.abs(y - z) == x
e. x < 10 && x > 10
f. x > y || y > x
g !(x < y + z) || !(x + 10 <= 20)
h. !(x == y) && (x != y) && (x < y ||
y < x)
7. Express the following switch statement using nested-if
statements.
switch (grade) {
case 10:
case 9:
a = 1;
b
= 2;
break;
case 8:
a = 3;
b
= 4;
break;
default:
a = 5;
break;
}
8. Write an if statement to find the smallest of three
given integers without
using the min method of the Math class.
9. Draw control flow diagrams for the following two
switch statements.
a. switch (choice) {
case 1:
a = 0;
break;
case 2:
b = 1;
break;
case 3:
c = 2;
break;
default:
d = 3;
break;
}
b. switch (choice) {
case 1:
a = 0;
case 2:
b = 1;
case 3:
c = 2;
default:
d = 3;
}
10. Write an if statement that prints out a message based
on the following
rules:
If the Total Points Are Message to Print
>=100
You won a free cup of coffee.
>=200
You won a free cup of coffee and
a
regular-size doughnut.
>=300
You won a free cup of coffee and
a
regular-size doughnut and
a
12-oz. orange juice.
>=400
You won a free cup of coffee and
a
regular-size doughnut and
a
12-oz. orange juice and
a
combo breakfast.
>=500
You won a free cup of coffee and
a
regular-size doughnut and
a
12-oz. orange juice and
a
combo breakfast and
a
reserved table for one week.
4. What's wrong with the following switch statement?
switch (N){
case 0:
case 1:
x= 11;
break;
default:
System.out.println("Switch Error");
break;
case 2:
x= 22;
break;
case 1:
x= 33;
break;
}
5. What's wrong with the following switch statement?
switch (ranking) {
case
> 4.55:
pay=pay*.20;
break;
case=
4.55:
pay
= pay * .15;
break;
default:
pay=
pay * .05;
break;
}