Why this statement is bad practice :
String colour= new String("Blue");
and what's difference with this statement
String colour="Blue";
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jww
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Eman Habib
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Possibly related: [String object instantiation](http://stackoverflow.com/q/16742819). – jww Jul 11 '15 at 01:24
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3*"Why this statement is bad practice"* - One reason is that it is pointless. Just like comments in your code about your favourite colour is. – Stephen C Jul 11 '15 at 01:26
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1This is because of the immutability of String. For more information have a look at this tutorial http://www.javahelps.com/2015/03/immutability-of-string.html – Gobinath Jul 11 '15 at 03:52
2 Answers
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The first is discouraged because it reads a String from the String intern pool and then instantiates a new object instance. The Wikipedia article on String interning says (in part)
In computer science, string interning is a method of storing only one copy of each distinct string value, which must be immutable. Interning strings makes some string processing tasks more time- or space-efficient at the cost of requiring more time when the string is created or interned. The distinct values are stored in a string intern pool.
The second example assigns a reference to the String from the intern pool.
Elliott Frisch
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1@MrMadsen No. You'd get a new object reference. `"Blue" != new String("Blue")` – Elliott Frisch Jul 11 '15 at 01:20
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2Indeed, the JLS >>guarantees<< that it will be a new object reference ... if there is any possibility that you can observe this. (And testing using `!=` is one way to observe it ...) – Stephen C Jul 11 '15 at 01:30
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You're creating an unnecessary String object.
String colour= new String("Blue");
"Blue" is already a String type.
ALD
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