IdentityCheck
From APIDesign
(Difference between revisions)
(New page: Is there an externally observable difference between following programs? public static String sayHello() { return "Hello World!"; } public static void sayHello() { return "Hello" + " ...) |
|||
| (2 intermediate revisions not shown.) | |||
| Line 1: | Line 1: | ||
Is there an externally observable difference between following programs? | Is there an externally observable difference between following programs? | ||
| + | <source lang="java"> | ||
public static String sayHello() { | public static String sayHello() { | ||
return "Hello World!"; | return "Hello World!"; | ||
} | } | ||
| - | public static | + | </source> |
| - | + | <source lang="java"> | |
| + | public static String sayHello() { | ||
| + | String s1 = "Hello"; | ||
| + | String s2 = " World!"; | ||
| + | return s1 + s2; | ||
} | } | ||
| + | </source> | ||
Of course, there is! Just call the method twice: | Of course, there is! Just call the method twice: | ||
Current revision
Is there an externally observable difference between following programs?
public static String sayHello() { return "Hello World!"; }
public static String sayHello() { String s1 = "Hello"; String s2 = " World!"; return s1 + s2; }
Of course, there is! Just call the method twice:
assert sayHello() == sayHello();
The first version of the method passes the IdentityCheck test. The second does not. There are also other differences in MemoryAllocations as well as StringsUsedInConstantPool.
Follow
