What is the difference between "ABC" and new String("ABC")?
difference, java, string
Solution
String
In Java `String` is a special object and allows you to create a new `String` without necessarily doing `new String("ABC")`. However `String s = "ABC"` and `String s = new String("ABC")` is not the same operation.
From the javadoc for `new String(String original)`:
Initializes a newly created String object so that it represents the same sequence of characters as the argument; [...]
Unless an explicit copy of original is needed, use of this constructor is unnecessary since Strings are immutable.
In other words doing `String s = new String("ABC")` creates a new instance of `String`, while `String s = "ABC"` reuse, if available, an instance of the String Constant Pool.
String Constant Pool
The String Constant Pool is where the collection of references to `String` objects are placed.
`String s = "prasad"` creates a new reference only if there isn't another one available. You can easily see that by using the `==` operator.
String s = "prasad";
String s2 = "prasad";
System.out.println(s == s2); // true
Image taken from thejavageek.com.
`new String("prasad")` always create a new reference, in other words `s` and `s2` from the example below will have the same value but won't be the same object.
String s = "prasad";
String s2 = new String("prasad");
System.out.println(s == s2); // false
Image taken from thejavageek.com.
Problem
What is difference between `String str = "ABC"` and `String str = new String("ABC")`?