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<div id="PageTitle"><h1>Comparing Strings and Portions of Strings</h1></div>
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<!-- Comparing Strings and Portions of Strings -->
<p>The <code>String</code> class has a number of methods for comparing strings and portions of strings. The following table lists these methods.</p>
<table width="100%" border="1" cellpadding="4" cellspacing="3" summary="This table lists methods for comparing strings">
<caption style="font-weight: bold">Methods for Comparing Strings</caption>
<tr>
<th id="h1">Method</th>
<th id="h2" width="50%">Description</th>
</tr>
<tr>
<td headers="h1"><code>boolean endsWith(String suffix)<br />
boolean startsWith(String prefix)</code></td>
<td headers="h2">Returns <code>true</code> if this string ends with or begins with the substring specified as an argument to the method.</td>
</tr>
<tr>
<td headers="h1"><code>boolean startsWith(String prefix, int offset)</code></td>
<td headers="h2">Considers the string beginning at the index <code>offset</code>, and returns <code>true</code> if it begins with the substring specified as an argument.</td>
</tr>
<tr>
<td headers="h1"><code>int compareTo(String anotherString)</code></td>
<td headers="h2">Compares two strings lexicographically. Returns an integer indicating whether this string is greater than (result is > 0), equal to (result is = 0), or less than (result is < 0) the argument.</td>
</tr>
<tr>
<td headers="h1"><code>int compareToIgnoreCase(String str)</code></td>
<td headers="h2">Compares two strings lexicographically, ignoring differences in case. Returns an integer indicating whether this string is greater than (result is > 0), equal to (result is = 0), or less than (result is < 0) the argument.</td>
</tr>
<tr>
<td headers="h1"><code>boolean equals(Object anObject)</code></td>
<td headers="h2">Returns <code>true</code> if and only if the argument is a <code>String</code> object that represents the same sequence of characters as this object.</td>
</tr>
<tr>
<td headers="h1"><code>boolean equalsIgnoreCase(String anotherString)</code></td>
<td headers="h2">Returns <code>true</code> if and only if the argument is a <code>String</code> object that represents the same sequence of characters as this object, ignoring differences in case.</td>
</tr>
<tr>
<td headers="h1"><code>boolean regionMatches(int toffset, String other, int ooffset, int len)</code></td>
<td headers="h2">Tests whether the specified region of this string matches the specified region of the String argument.
<p>Region is of length <code>len</code> and begins at the index <code>toffset</code> for this string and <code>ooffset</code> for the other string.</p>
</td>
</tr>
<tr>
<td headers="h1"><code>boolean regionMatches(boolean ignoreCase, int toffset, String other, int ooffset, int len)</code></td>
<td headers="h2">Tests whether the specified region of this string matches the specified region of the String argument.
<p>Region is of length <code>len</code> and begins at the index <code>toffset</code> for this string and <code>ooffset</code> for the other string.</p>
<p>The boolean argument indicates whether case should be ignored; if true, case is ignored when comparing characters.</p>
</td>
</tr>
<tr>
<td headers="h1"><code>boolean matches(String regex)</code></td>
<td headers="h2">Tests whether this string matches the specified regular expression. Regular expressions are discussed in the lesson titled "Regular Expressions."</td>
</tr>
</table>
<p>The following program, <code>RegionMatchesDemo</code>, uses the <code>regionMatches</code> method to search for a string within another string:</p>
<div class="codeblock"><pre>
public class RegionMatchesDemo {
public static void main(String[] args) {
String searchMe = "Green Eggs and Ham";
String findMe = "Eggs";
int searchMeLength = searchMe.length();
int findMeLength = findMe.length();
boolean foundIt = false;
for (int i = 0;
i <= (searchMeLength - findMeLength);
i++) {
if (searchMe.regionMatches(i, findMe, 0, findMeLength)) {
foundIt = true;
System.out.println(searchMe.substring(i, i + findMeLength));
break;
}
}
if (!foundIt)
System.out.println("No match found.");
}
}
</pre></div>
<p>The output from this program is <code>Eggs</code>.</p>
<p>The program steps through the string referred to by <code>searchMe</code> one character at a time. For each character, the program calls the regionMatches method to determine whether the substring beginning with the current character matches the string the program is looking for.</p>
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