Java 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.
Explained
The substring( ) method constructs a new String object made up of 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 method 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);
}
When run, this prints the following:
> java SubStringDemo
Java is great.
is great.
is
is great.
>
No comments:
Post a Comment