String

• Immutable
• Thread-safe by default (immutable, no need extra sync)
• Stored in String Pool (a storage area in Heap)
  • String have high chance to be the same value, so try to decrease a lot of same String object.
  • If object is mutable, cant share, since keep changing.
  • Hence, String is immutable.
  • Also dafer in case of Hashtables / HashMaps, to ensure getting the immutable value.

// String name = “MH”; in string pool

// String name = new String(”MH”); in heap

StringBuilder

• Heap memory is the storage area.
• Mutable.
• Fastest.
• Not thread-safe.

StringBuffer

• Heap memory is the storage area.
• Mutable.
• Thread-safe.