groovy/jsr/spec/src/wiki/Chapter14Blocks

*Chapter 14*

h1. Blocks and Statements
The organization of this chapter parallels the chapter on [Blocks and Statements|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html] in the [Java Language Specification (second edition)|http://java.sun.com/docs/books/jls/second_edition/html/j.title.doc.html], which begins as follows:

bq. The sequence of execution of a program is controlled by ??statements??, which are executed for their effect and do not have values.

bq. Some statements ??contain?? other statements as part of their structure; such other statements are substatements of the statement. We say that statement _S_ ??immediately  contains?? statement _U_ if there is no statement _T_ different from _S_ and _U_ such that _S_ contains _T_ and _T_ contains _U_. In the same manner, some statements contain expressions ([§15|Chapter 15 Expressions#15], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/expressions.doc.html#4709]) as part of their structure.

bq. The first section of this chapter discusses the distinction between normal and abrupt completion of statements ([§14.1|Chapter 14 Blocks#14.1], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5894]). Most of the remaining sections explain the various kinds of statements, describing in detail both their normal behavior and any special treatment of abrupt completion.

bq. Blocks are explained first ([§14.2|Chapter 14 Blocks#14.2], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#246838]), followed by local class declarations ([§14.3|Chapter 14 Blocks#14.3], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#247766]) and local variable declaration statements ([§14.4|Chapter 14 Blocks#14.4], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5920]). 

bq. Next a grammatical maneuver that sidesteps the familiar "dangling {{else}}" problem ([§14.5|Chapter 14 Blocks#14.5], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#32584]) is explained.

bq. Statements that will be familiar to C and C++ programmers are the empty ([§14.6|Chapter 14 Blocks#14.6], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5970]), labeled ([§14.7|Chapter 14 Blocks#14.7], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#78993]), expression ([§14.8|Chapter 14 Blocks#14.8], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5984]), {{if}} ([§14.9|Chapter 14 Blocks#14.9], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5991]), {{switch}} ([§14.10|Chapter 14 Blocks#14.10], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#35518]), {{while}} ([§14.11|Chapter 14 Blocks#14.11], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#237277]), {{do}} ([§14.12|Chapter 14 Blocks#14.12], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#6045]), {{for}} ([§14.13|Chapter 14 Blocks#14.13], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#24588]), {{break}} ([§14.14|Chapter 14 Blocks#14.14], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#6842]), {{continue}} ([§14.15|Chapter 14 Blocks#14.15], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#6122]), and {{return}} ([§14.16|Chapter 14 Blocks#14.16], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#6767]) statements.

bq. Unlike C and C++, the Java programming language has no {{goto}} statement. However, the {{break}} and {{continue}} statements are allowed to mention statement labels.

bq. The Java programming language statements that are not in the C language are the {{throw}} ([§14.17|Chapter 14 Blocks#14.17], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#237350]), {{synchronized}} ([§14.18|Chapter 14 Blocks#14.18], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#255769]), and {{try}} ([§14.19|Chapter 14 Blocks#14.19], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#79311]) statements.

bq. The last section ([§14.20|Chapter 14 Blocks#14.20], [JLS|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#236365]) of this chapter addresses the requirement that every statement be ??reachable?? in a certain technical sense.

{anchor:14.1}
h2. 14.1 Normal and Abrupt Completion of Statements
(Cf. ??[JLS. §14.1|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5894]??.)

TO DO

{anchor:14.2}
h2. 14.2 Blocks
(Cf. ??[JLS. §14.2|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#246838]??.)

TO DO

{anchor:14.3}
h2. 14.3 Local Class Declarations
(Cf. ??[JLS. §14.3|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#247766]??.)

TO DO

{anchor:14.4}
h2. 14.4 Local Variable Declaration Statements
(Cf. ??[JLS. §14.4|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5920]??.)

TO DO

{anchor:14.4.1}
h3. 14.4.1 Local Variable Declarators and Types
(Cf. ??[JLS. §14.4.1|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#35393]??.)

TO DO

{anchor:14.4.2}
h3. 14.4.2 Scope of Local Variable Declarations
(Cf. ??[JLS. §14.4.2|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#32644]??.)

TO DO

{anchor:14.4.3}
h3. 14.4.3 Shadowing of Names by Local Variables
(Cf. ??[JLS. §14.4.3|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#32716]??.)

TO DO

{anchor:14.4.4}
h3. 14.4.4 Execution of Local Variable Declarations
(Cf. ??[JLS. §14.4.4|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#32717]??.)

TO DO

{anchor:14.5}
h2. 14.5 Statements
(Cf. ??[JLS. §14.5|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#32584]??.)

TO DO

{anchor:14.6}
h2. 14.6 The Empty Statement
(Cf. ??[JLS. §14.6|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5970]??.)

TO DO

{anchor:14.7}
h2. 14.7 Labeled Statements
(Cf. ??[JLS. §14.7|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#78993]??.)

TO DO

{anchor:14.8}
h2. 14.8 Expression Statements
(Cf. ??[JLS. §14.8|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5984]??.)

TO DO

{anchor:14.9}
h2. 14.9 The <code>if Statement</h2>
(Cf. ??[JLS. &#167;14.9|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#5991]??.)

TO DO

{anchor:14.9.1}
h3. 14.9.1 The <code>if-then Statement</h3>
(Cf. ??[JLS. &#167;14.9.1|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#237433]??.)

TO DO

{anchor:14.9.2}
h3. 14.9.2 The <code>if-then-else Statement</h3>
(Cf. ??[JLS. &#167;14.9.2|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#236506]??.)

TO DO

{anchor:14.10}
h2. 14.10 The <code>switch Statement</h2>
(Cf. ??[JLS. &#167;14.10|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#35522]??.)

TO DO

{anchor:14.11}
h2. 14.11 The while Statement
(Cf. ??[JLS. &#167;14.11|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#237278]??.)

TO DO

{anchor:14.11.1}
h3. 14.11.1 Abrupt Completion
(Cf. ??[JLS. &#167;14.11.1|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#21139]??.)

TO DO

{anchor:14.12}
h2. 14.12 The do Statement
(Cf. ??[JLS. &#167;14.12|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#246911]??.)

TO DO

{anchor:14.12.1}
h3. 14.12.1 Abrupt Completion
(Cf. ??[JLS. &#167;14.12.1|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#45366]??.)

TO DO

{anchor:14.12.2}
h3. 14.12.2 Example of do statement
(Cf. ??[JLS. &#167;14.12.2|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#252264]??.)

TO DO

{anchor:14.13}
h2. 14.13 The <code>for Statement</h2>
(Cf. ??[JLS. &#167;14.13|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#24588]??.)

TO DO

{anchor:14.13.1}
h3. 14.13.1 Initialization of <code>for statement</h3>
(Cf. ??[JLS. &#167;14.13.1|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#45367]??.)

TO DO

{anchor:14.13.2}
h3. 14.13.2 Iteration of for statement
(Cf. ??[JLS. &#167;14.13.2|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#217196]??.)

TO DO

{anchor:14.13.3}
h3. 14.13.3 Abrupt Completion of <code>for statement</h3>
(Cf. ??[JLS. &#167;14.13.3|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#45371]??.)

TO DO

{anchor:14.14}
h2. 14.14 The <code>break Statement</h2>
(Cf. ??[JLS. &#167;14.14|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#35540]??.)

TO DO

{anchor:14.15}
h2. 14.15 The <code>continue Statement</h2>
(Cf. ??[JLS. &#167;14.15|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#6122]??.)

TO DO

{anchor:14.16}
h2. 14.16 The <code>return Statement</h2>
(Cf. ??[JLS. &#167;14.16|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#6767]??.)

TO DO

{anchor:14.17}
h2. 14.17 The <code>throw Statement</h2>
(Cf. ??[JLS. &#167;14.17|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#237350]??.)

TO DO

{anchor:14.18}
h2. 14.18 The <code>synchronized Statement</h2>
(Cf. ??[JLS. &#167;14.18|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#255769]??.)

TO DO

{anchor:14.19}
h2. 14.19 The <code>try statement</h2>
(Cf. ??[JLS. &#167;14.19|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#79311]??.)

TO DO

{anchor:14.19.1}
h3. 14.19.1 Execution of try-catch<code><b></code></h3>
(Cf. ??[JLS. &#167;14.19.1|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#24134]??.)

TO DO

{anchor:14.19.2}
h3. 14.19.2 Execution of try-catch-finally<code><b></code></h3>
(Cf. ??[JLS. &#167;14.19.2|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#79326]??.)

TO DO

{anchor:14.20}
h2. 14.20 Unreachable Statements
(Cf. ??[JLS. &#167;14.20|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html#236365]??.)

TO DO

----
Specification [Table of Contents|Chapter 00 Contents].

The organization of this chapter parallels the chapter on [Blocks and Statements|http://java.sun.com/docs/books/jls/second_edition/html/statements.doc.html] in the [Java Language Specification (second edition)|http://java.sun.com/docs/books/jls/second_edition/html/j.title.doc.html].

The original of this specification is at [http://docs.codehaus.org/display/GroovyJSR].