Sams Teach Yourself Java™ in 24 Hours (Covering Java 7 and Android)

ptg7068951

ifStatements 81

if (account <= 0) {
System.out.println(“You are flat broke”);
}

There’s also a >=operator for greater-than-or-equal-to tests.

Equal and Not Equal Comparisons

Anothercondition to check in a program is equality. Is a variable equal to a
specific value? Is one variable equal to the value of another? These ques-
tions can be answered with the==operator, as in the following statements:

if (answer == rightAnswer) {
studentGrade = studentGrade + 10;
}

if (studentGrade == 100) {
System.out.println(“Show off!”);

}

You also can test inequality, whether something is not equal to something
else, with the!=operator, as follows:

if (answer != rightAnswer) {
score = score - 5;
}

You can use the ==and !=operators with every type of variable except for
strings, because strings are objects.

Organizing a Program with Block Statements

Up to this point, the ifstatements in this hour have been accompanied by
a block contained within the {and }brackets. (I believe the technical term
for these characters is “squiggly bracket marks.”)

Previously, you have seen how block statements are used to mark the
beginning and end of the main()block of a Java program. Each statement
within the main()block is handled when the program is run.

An ifstatement does not require a block statement. It can occupy a single
line, as in this example:

if (account <= 0) System.out.println(“No more money”);

CAUTION

The operator used to conduct

equality tests has two equal

signs:==. It’s easy to confuse

this operator with the =opera-

tor,which is used to give a

value to a variable. Always use

two equal signs in a conditional

statement.