4 Comparing Strings.pdf - Decisions in Java – Comparing...

Decisions in Java – Comparing Strings
Comparing Strings
The relational operators used with the primitive data types (i.e., less than, greater than, equal to, etc.)
should not be used to compare strings. Recall that a String variable does not actually contain the
string, but only the location (address) of the string object in memory. Thus any comparison between
strings using relational operators would actually be comparing two addresses, rather than the String
values.
Java provides a number of methods for comparing strings, but for now we will introduce only the
equals and the compareTo methods. These are String methods , which means it can be called from
any String variable .
The equals method – testing for identical strings
The equals method tests whether or not two strings are identical , returning true if they are identical,
and false otherwise.
Example 1 – given the declaration
String s = "Same";
then the equals method would yield the following results:
a)
s.equals("Same") will return true
b)
s.equals("same") will return false because 'S' is not equal to 's'
c) s.equals("Same ") will return false because of the spaces at the end of the word