CONTROL STRUCTURES I: SELECTION - Java Programming: From Problem Analysis to Program Design - page 230

Next, consider the following statements:
String str3 = new String("Hello");
String str4 = new String("Hello");
When the first statement executes, a String object with the value "Hello" is created
and its address is assigned to str3 . When the second statement executes, another
String object with the value "Hello" is created and its address is assigned to str4
(see Figure 4-8).

str3 Hello

str4 Hello

FIGURE 4-8 Variables str3 , str4 , and the objects to which they point

It follows that the expression (str3 == str4) evaluates to false . However, the
expression str3.equals(str4) evaluates to true .

The program StringObjectsAndTheOprNew.java , which shows the effect of
the preceding statements, can be found in the Additional Student Files folder at
www.cengagebrain.com.

QUICK REVIEW

1 . Control structures alter the sequential flow of control.
2 . The two most common activities provided by control structures are selection
and repetition.
3 . Selection structures incorporate decisions in a program.
4 . The Java relational operators are == (equality), != (not equal to), < (less
than), <= (less than or equal to), > (greater than), and >= (greater than or
equal to).
5 . Including a space within the relational operators == , <= , >= , and != creates
a syntax error. (For example, = = will create a syntax error.)
6 . Characters are compared using the collating sequence of the Unicode
character set.

7 .

Logical (boolean) expressions evaluate to true or false .

8 .

In Java, boolean variables are used to store the value of a logical expression.