BLOCKS AND STATEMENTS

Statements

14.4

hidden field

x

, using the form

this.x

. Indeed, this idiom typically appears in con 

structors ( 8.6):

class Pair {

Object first, second;

public Pair(Object first, Object second) {

this.first = first;

this.second = second;

}

}

In this example, the constructor takes parameters having the same names as the

fields to be initialized. This is simpler than having to invent different names for

the parameters and is not too confusing in this stylized context. In general, how 

ever, it is considered poor style to have local variables with the same names as

fields.

14.3.4   Execution of Local Variable Declarations

A local variable declaration statement is an executable statement. Every time it is

executed, the declarators are processed in order from left to right. If a declarator

has an initialization expression, the expression is evaluated and its value is

assigned to the variable. If a declarator does not have an initialization expression,

then a Java compiler must prove, using exactly the algorithm given in  16, that

every reference to the variable is necessarily preceded by execution of an assign 

ment to the variable. If this is not the case, then a compile time error occurs.

Each initialization (except the first) is executed only if the evaluation of the

preceding initialization expression completes normally. Execution of the local

variable declaration completes normally only if evaluation of the last initialization

expression completes normally; if the local variable declaration contains no ini 

tialization expressions, then executing it always completes normally.

14.4   Statements

There are many kinds of statements in the Java language. Most correspond to

statements in the C and C++ languages, but some are unique to Java.

As in C and C++, the Java

if

 statement suffers from the so called  dangling

else

 problem,  illustrated by this misleadingly formatted example:

if (door.isOpen())

if (resident.isVisible())

resident.greet("Hello!");

else door.bell.ring();

//

A  dangling

else

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