What is Compile Time constant expression value inlined by compiler in JAVA?

Question

Recently i was reading i got this

"When you declare a String (which is immutable) variable as final, and initialize it with a compile-time constant expression, it also becomes a compile-time constant expression, and its value is inlined by the compiler where it is used."

and "i'm really confused what does this mean its value is inlined by compiler" ? Please explain it in Simple way if possible

Source of the above line

Inling basically means "replacing the calls to the variable/method with the actual value or code contained in the method". It's a performance consideration. — Jeroen Vannevel, Apr 22 '15 at 18:12
Possible duplicate of http://stackoverflow.com/questions/9082971/compile-time-constants-and-variables — dhke, Apr 22 '15 at 18:13

EvenLisle · Answer 1 · 2015-04-22T18:10:10.883

2

When a String is finalized and initialized at compile time, the compiler can copy-paste the string into the code, instead of looking up the variable at every use. Similar to inline expansion.

final String a = "asd";
String b = a;

The above snippet becomes

final String a = "asd";
String b = "asd";

edited Apr 22 '15 at 18:10

answered Apr 22 '15 at 18:07

EvenLisle

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What is Compile Time constant expression value inlined by compiler in JAVA?

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