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K&B book chapter 1 Q.No.15

 
Lakshmi Saradha
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The question is
Which four describe the correct default values for array elements of the types indicated?
a)int =>0
b) String =>"null"
c) Dog => null
d)char =>'\u0000'
e)float => 0.0f
f) boolean => true
The answers given are a,c,d,e
I have a question regarding the option e)
Arrays are always initialised with default values and float-point variables are defined as double by default..Is e) a right choice?
 
Vad Fogel
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An array of floats can only hold float type compatible elements (double is larger). The default value of any element is of type float.
Refer JLS:

4.5.1 Variables of Primitive Type
A variable of a primitive type always holds a value of that exact primitive type.


4.5.3 Kinds of Variables
Array components are unnamed variables that are created and initialized to
default values (�4.5.5) whenever a new object that is an array is created
(�15.10). The array components effectively cease to exist when the array is no
longer referenced. See �10 for a description of arrays.

[ November 03, 2003: Message edited by: Vad Fogel ]
 
Derek Baker
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Arrays are always initialised with default values and float-point variables are defined as double by default..Is e) a right choice?[/QB]

I think what you are referring to is assigning a floating point literal to a variable. If you don't specify that is is a float by appending an 'f' it will be a double by default. When an array is initialized, however, if it is to contain floats, then the JVM will insert the default *float* value (not the default floating-point value).
 
Lakshmi Saradha
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thank you..
 
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