Boolean.valueOf(boolean) vs Boolean.valueOf(String)

[Abhishek Asthana]

From the Boolean javadoc:

public static Boolean valueOf(boolean b)

Parameters:
b - a boolean value.
Returns:
a Boolean instance representing b.

Wheras:

public static Boolean valueOf(String s)

Parameters:
s - a string.
Returns:
the Boolean value represented by the string.

What I am not able to understand is that since for both methods return type is same, how come for one a new Boolean instance is being returned and for the other boolean primitive is being returned.

Any pointers will help.

Thanks
Abhishek

[Matthew Brown]

What makes you think a boolean primitive is being returned by either of them, since the Javadocs say that both return a Boolean object?

[Abhishek Asthana]

Detailed from the javadoc:

public static Boolean valueOf(boolean b)

Returns a Boolean instance representing the specified boolean value. If the specified boolean value is true, this method returns Boolean.TRUE; if it is false, this method returns Boolean.FALSE.

Parameters:
b - a boolean value.
Returns:
a Boolean instance representing b.

public static Boolean valueOf(String s)

Returns a Boolean with a value represented by the specified String. The Boolean returned represents the value true if the string argument is not null and is equal, ignoring case, to the string "true".
Example: Boolean.valueOf("True") returns true.
Example: Boolean.valueOf("yes") returns false.

Parameters:
s - a string.
Returns:
the Boolean value represented by the string.

And since the second method does not return an instance, it is recommended to be used instead of constructor Boolean(String value).

[Henry Wong]

Abhishek Asthana wrote:Detailed from the javadoc:

Agreed with Matthew. And I am not sure how this detail from javadoc is to be used to confirm the original question. The JavaDoc clearly states that both methods return a Boolean instance, and not a primative.

[EDIT] Oh I see now. In the example of the Javadoc (and not in the latest java 6 doc), the author mistakenly used lower case. Regardless, if you look at the signature of the method, two lines up, it is obvious that it is a documentation error.... And BTW, it looks like the java 6 javadoc remove those statements entirely.


Henry