CONTROL STRUCTURES I: SELECTION - Java Programming: From Problem Analysis to Program Design - page 232

23 . To use the method compareTo , you use the expression:
str1.compareTo(str2)
where str1 and str2 are String variables. Moreover, str2 can also be a
String constant (literal). The expression str1.compareTo(str2) evalu-
ates as follows:

(

an integer value less than 0 if string str1
is less than string str2
0 if string str1 is equal to string str2
an integer value greater than 0 if string str1
is greater than string str2

str1.compareTo(str2) =

EXERCISES

1. Mark the following statements as true or false.
a. The result of a logical expression cannot be assigned to an int variable.
b. In a one-way selection, if a semicolon is placed after the expression in an
if statement, the expression in the if statement is always true .
c. Every if statement must have a corresponding else .
d. The expression:

(ch >= 'A' && ch <= 'Z')

evaluates to false if either ch < 'A' or ch >= 'Z' .

Suppose the input is 5 . (Assume that all variables are properly declared.)
The output of the code:

e.

num = console.nextInt();
if (num > 5)
System.out.println(num);
num = 0;
else
System.out.println("Num is zero");

is:
Num is zero.

f. The expression in a switch statement should evaluate to a value of any
primitive data type.
g. The expression !(x > 0) is true only if x is a negative number.
h. In Java, both ! and != are logical operators.
i. The order in which statements execute in a program is called the flow
of control.