Decisions - Java Concepts - page 261

Do not use the == operator to compare strings. The expression

if (string1 == string2) // Not useful

has an unrelated meaning. It tests whether the two string variables refer to the
identical string object. You can have strings with identical contents stored in
different objects, so this test never makes sense in actual programming; see
Common Error 5.1 .

In Java, letter case matters. For example, ÐHarryÑ and ȒHARRYȓ are not the
same string. To ignore the letter case, use the equal sIgnoreCase method:

if (string1.equalsIgnoreCase(string2)) . . .

If two strings are not identical to each other, you still may want to know the
relationship between them. The compareTo method compares strings in
dictionary order. If

The compareTo method compares strings in dictionary order.

string1.compareTo (string2) < 0

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Figure 3

Lexicographic Comparison

then the string string1 comes before the string string2 in the dictionary. For
example, this is the case if string1 is ÐHarryÑ , and string2 is ÐHelloÑ . If

string1.compareTo(string2) > 0

then string1 comes after string2 in dictionary order. Finally, if

string1. compareTo (string2) == 0