Taking Strings Apart with Substrings
Problem
You want to break a string apart into substrings by position.
Solution
Use the String object’s substring( ) method.
Discussion
The substring( )
method constructs a new
String object made up from a run of characters
contained somewhere in the original string, the one whose
substring( ) you called. The name of this method,
substring(), violates the stylistic dictum that
words should be capitalized; if Java were 100.0% consistent, this
would be named subString. But it’s not;
it’s substring. The
substring method is
overloaded:
both forms require a
starting
index. The one-argument form returns
from startIndex to the end. The two-argument form
takes an ending index (not a length, as in some languages), so that
an index can be generated by the String methods
indexOf( )
or
lastIndexOf( ). Note that the end index is one
beyond the last character!
// File SubStringDemo.java
public static void main(String[] av) {
String a = "Java is great.";
System.out.println(a);
String b = a.substring(5); // b is the String "is great."
System.out.println(b);
String c = a.substring(5,7);// c is the String "is"
System.out.println(c);
String d = a.substring(5,a.length( ));// d is "is great."
System.out.println(d);
}This prints the following when run:
> java SubStringDemo Java is great. is great. is is great. >