16.2

Definite Assignment and Statements

DEFINITE ASSIGNMENT

For any immediate subexpression

y

 of an expression

x

,

V

 is definitely assigned

before

y

 iff

V

 is definitely assigned before

x

 or one of the following situations is

true:

y

 is the right hand operand of a binary operator and

V

 is definitely assigned

after the left hand operand.

x

 is an array reference,

y

 is the subexpression within the brackets, and

V

 is def 

initely assigned after the subexpression before the brackets.

x

 is a method invocation expression for an object;

y

 is the first argument

expression in the method invocation expression; there is a subexpression

whose value is an object to the left of the dot, method name, and left parenthe 

sis of the method invocation expression; and

V

 is definitely assigned after this

subexpression.

x

 is a method invocation expression or class instance creation expression;

y

 is

an argument expression, but not the first; and

V

 is definitely assigned after the

argument expression to the left of

y

.

x

 is an class instance creation expression;

y

 is a dimension expression, but not

the first; and

V

 is definitely assigned after the dimension expression to the left

of

y

.

16.2   Definite Assignment and Statements

16.2.1   Empty Statements

V

 is definitely assigned after an empty statement iff it is definitely assigned

before the empty statement.

16.2.2   Blocks

V

 is definitely assigned after an empty block iff it is definitely assigned before

the empty block.

V

 is definitely assigned after a nonempty block iff it is definitely assigned after

the last statement in the block.

V

 is definitely assigned before the first statement of the block iff it is definitely

assigned before the block.

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