In Java, the String class, String-Buffer, and String-Builder are classes used to work with text data, but they have different characteristics and are suited for different scenarios.
System
- java.lang.System is a final class exposing utility functions
- Some fields & methods:-
- public static final java.io.PrintStream out;
- public static final java.io.PrintStream err;
- public static final java.io.InputStream in;
- public static long currentTimeMillis();
- public static Sring getProperty(String propName);
String str = "Hello";
str = str + " World";
// Creates a new string object
String Classes : String
- java.lang.String Represents a piece of text or set of characters.
- Immutable, hence thread safe.
- String pooling
- Some methods
- public int length()
- public String subString(int beginIndex)
- public String[] split (String regex)
String Classes : StringBuffer
- java.lang.StringBuffer is used for string manipulation. .
- It is mutable, unlike java.lang.String.
- It is thread-safe, hence little expensive to work with.
StringBuffer buffer = new StringBuffer
("Hello");
buffer.append(" World");
// Modifies the existing buffer
Java counts positions from zero.
0 is the first position in a string, 1 is the second, 2 is the third …
String Classes : StringBuilder
- java.lang.StringBuilder is used for string manipulation.
- It is also mutable, like java.lang.StringBuffer.
- It is not thread-safe, hence useful where we don’t need shared resources.
- Some methods are :-
- public int capacity()
- public StringBuilder append(String args)
- public StringBuilder insert (int offset, String args)
StringBuilder builder =
new StringBuilder("Hello");
builder.append(" World");
// Modifies the existing builder
