Arrays and Strings - Beginning Java 2 SDK - page 150

public class ExtractSubstring {
public static void main(String[] args) {
String text = "To be or not to be"; // String to be segmented
int count = 0; // Number of substrings
char separator = ' '; // Substring separator
// Determine the number of substrings
int index = 0;
do {
++count; // Increment count of substrings
++index; // Move past last position
index = text.indexOf(separator, index);
} while (index != -1);
// Extract the substring into an array
String[] subStr = new String[count]; // Allocate for substrings
index = 0; // Substring start index
int endIndex = 0; // Substring end index
for(int i = 0; i < count; i++) {
endIndex = text.indexOf(separator,index); // Find next separator
if(endIndex == -1) // If it is not found
subStr[i] = text.substring(index); // extract to the end
else // otherwise
subStr[i] = text.substring(index, endIndex); // to end index
index = endIndex + 1; // Set start for next cycle
}
// Display the substrings
for(int i = 0; i < subStr.length; i++)
System.out.println(subStr[i]);
}
}
When you run this example, you should get the output:
To
be
or
not
to
be
How It Works
After setting up the string text to be segmented into substrings, a count variable to hold the number
of substrings, and the separator character, separator , the program has three distinct phases.
The first phase counts the number of substrings by using the indexOf() method to find separators.
The number of separators is always one less than the number of substrings. By using the do-while
loop, we ensure that the value of count will be one more than the number of separators.