When // doStuff is reached, how many objects are eligible for GC?
A. 0
B. 1
C. 2
D. Compilation fails.
E. It is not possible to know.
F. An exception is thrown at runtime.

Answer:
® 3 C is correct. Only one CardBoard object (c1) is eligible, but it has an associated Short
wrapper object that is also eligible.
®˚ A, B, D, E, and F are incorrect based on the above. (Objective 7.4)

Omeganosferatu wrote:Não entendi esse lance do pool .... Não vejo problemas na resposta do livro

java.lang.Short wrote: /** * Returns a <code>Short</code> object holding the * value given by the specified <code>String</code>. The argument * is interpreted as representing a signed decimal * <code>short</code>, exactly as if the argument were given to * the {@link #parseShort(java.lang.String)} method. The result is * a <code>Short</code> object that represents the * <code>short</code> value specified by the string. <p> In other * words, this method returns a <code>Byte</code> object equal to * the value of: * * <blockquote><code> * new Short(Short.parseShort(s)) * </code></blockquote> * * @param s the string to be parsed * @return a <code>Short</code> object holding the value * represented by the string argument * @exception NumberFormatException If the <code>String</code> does * not contain a parsable <code>short</code>. */ public static Short valueOf(String s) throws NumberFormatException { return valueOf(s, 10); } private static class ShortCache { private ShortCache(){} static final Short cache[] = new Short[-(-128) + 127 + 1]; static { for(int i = 0; i < cache.length; i++) cache[i] = new Short((short)(i - 128)); } } /** * Returns a <tt>Short</tt> instance representing the specified * <tt>short</tt> value. * If a new <tt>Short</tt> instance is not required, this method * should generally be used in preference to the constructor * {@link #Short(short)}, as this method is likely to yield * significantly better space and time performance by caching * frequently requested values. * * @param s a short value. * @return a <tt>Short</tt> instance representing <tt>s</tt>. * @since 1.5 */ public static Short valueOf(short s) { final int offset = 128; int sAsInt = s; if (sAsInt >= -128 && sAsInt <= 127) { // must cache return ShortCache.cache[sAsInt + offset]; } return new Short(s); }