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Order of Initialization

faisal usmani
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Joined: Jan 14, 2006
Posts: 139
Hello ranchers ,

I have this small question , what is the order of initialization when an object is instantiated ,when is constructor block executed

I think first the static variable or a static block is loaded , then the class variables are initialized and then a call to constructor is made .


Hope you got my point
Keith Lynn
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Joined: Feb 07, 2005
Posts: 2367
This is from the Java Language Specification.

Just before a reference to the newly created object is returned as the result, the indicated constructor is processed to initialize the new object using the following procedure:

1. Assign the arguments for the constructor to newly created parameter variables for this constructor invocation.
2. If this constructor begins with an explicit constructor invocation of another constructor in the same class (using this), then evaluate the arguments and process that constructor invocation recursively using these same five steps. If that constructor invocation completes abruptly, then this procedure completes abruptly for the same reason; otherwise, continue with step 5.
3. This constructor does not begin with an explicit constructor invocation of another constructor in the same class (using this). If this constructor is for a class other than Object, then this constructor will begin with an explicit or implicit invocation of a superclass constructor (using super). Evaluate the arguments and process that superclass constructor invocation recursively using these same five steps. If that constructor invocation completes abruptly, then this procedure completes abruptly for the same reason. Otherwise, continue with step 4.
4. Execute the instance initializers and instance variable initializers for this class, assigning the values of instance variable initializers to the corresponding instance variables, in the left-to-right order in which they appear textually in the source code for the class. If execution of any of these initializers results in an exception, then no further initializers are processed and this procedure completes abruptly with that same exception. Otherwise, continue with step 5. (In some early implementations, the compiler incorrectly omitted the code to initialize a field if the field initializer expression was a constant expression whose value was equal to the default initialization value for its type.)
5. Execute the rest of the body of this constructor. If that execution completes abruptly, then this procedure completes abruptly for the same reason. Otherwise, this procedure completes normally.


faisal usmani
Ranch Hand

Joined: Jan 14, 2006
Posts: 139
Thanx Keith !
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Order of Initialization