SEI CERT Oracle Coding Standard for Java

Space shortcuts

Page tree

Versions Compared

Old Version 13

changes.mady.by.user Ankur Goyal

Saved on

compared with

New Version 14

changes.mady.by.user Ankur Goyal

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.
Comment: Edited by NavBot

...

Wiki Markup
As detailed in the Java Language Specification \[[JLS 05|AA. Java References#JLS 05]\] section 14.14.2, ""The enhanced {{for}} statement"", an enhanced {{for}} statement of the form:

...

Code Block
bgColor#FFCCCC
Character[] array = new Character[10];
for(Character c: array) 
  c = 'x'; // initialization attempt

for(int i=0;i&lt;arrayi<array.length;i++) 
  System.out.print(array[i]);  // prints 10 &quot;null&quot;"null" values

Note that if c is declared final, a compiler error results when an attempt is made to initialize it.

...

Code Block
bgColor#ccccff
Character[] array = new Character[10];
for(int i = 0; i &lt;< array.length; i++) 
  array[i] = 'x';

for(final Character c: array) 
  System.out.print(c);  // prints 10 &quot;x&quot;"x" values

Risk Assessment

Attempts to assign to the loop variable from within the enhanced for loop (for-each idiom) are futile and may leave the class in a fragile, inconsistent state.

...

Wiki Markup
\[[JLS 05|AA. Java References#JLS 05]\] Section [14.14.2|http://java.sun.com/docs/books/jls/third_edition/html/statements.html#14.14.2] &quot;"The enhanced for statement&quot;"

...

DCL08-J. Enforce compile-time type checking of variable argument types&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;      03. Declarations and Initialization (DCL)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;      DCL31-J. Qualify mathematical constants with the static and final modifiers