trim( )
The trim( ) method returns a copy of the invoking string from which any leading and trailing
whitespace has been removed. It has this general form:
String trim( )
Here is an example:
String s = "
Hello World
".trim();
This puts the string "Hello World" into s.
The trim( ) method is quite useful when you process user commands. For example, the
following program prompts the user for the name of a state and then displays that state's
capital. It uses trim( ) to remove any leading or trailing whitespace that may have inadvertently
been entered by the user.
// Using trim() to process commands.
import java.io.*;
class UseTrim {
public static void main(String args[])
throws IOException
{
// create a BufferedReader using System.in
BufferedReader br = new
BufferedReader(new InputStreamReader(System.in));
String str;
System.out.println("Enter 'stop' to quit.");
System.out.println("Enter State: ");
do {
str = br.readLine();
str = str.trim(); // remove whitespace
if(str.equals("Illinois"))
System.out.println("Capital is Springfield.");
else if(str.equals("Missouri"))
System.out.println("Capital is Jefferson City.");
else if(str.equals("California"))
System.out.println("Capital is Sacramento.");
else if(str.equals("Washington"))
System.out.println("Capital is Olympia.");
// ...
} while(!str.equals("stop"));
}
}
Data Conversion Using valueOf( )
The valueOf( ) method converts data from its internal format into a human-readable form.
It is a static method that is overloaded within String for all of Java's built-in types so that each
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