2. EBNF and Syntax Graph

1. EBNF and Syntax Diagram

<program> ::= begin<stmt_list>end
<stmt_list> ::= <stmt>{“;”<stmt>}
<stmt> ::= <var>”=”<expression>
<var> ::= A|B|C
<expression> ::= <var>[(+|-)<var>]

Here’s a breakdown of the syntax diagram based on the EBNF description provided:

1. <program>:

   • It starts with "begin".
   • It contains <stmt_list>.
   • It ends with "end".

2. <stmt_list>:

   • It contains one or more <stmt> separated by ";".
   • The braces {} indicate repetition.

3. <stmt>:

   • It consists of a <var> followed by "=", followed by an <expression>.

4. <var>:

   • It can be either "A", "B", or "C".

5. <expression>:

   • It consists of a <var>.
   • Optionally, it may have a "+" or "-" followed by another <var>.

Corresponding Syntax Diagram:

Here’s how the elements would look as a syntax diagram:

• <program>:

  +-----------+
  |   begin   |
  +-----------+
        |
  +----------------+
  |  <stmt_list>    |
  +----------------+
        |
  +-----------+
  |    end    |
  +-----------+

• <stmt_list>:

  +--------------------+
  |  <stmt>            |
  +--------------------+
        |
  +---------------------+
  |  ";"  <stmt> (repeat)|
  +---------------------+

• <stmt>:

  +----------+      +------+      +---------------+
  |  <var>   | ---> |  "=" | ---> | <expression>  |
  +----------+      +------+      +---------------+

• <var>:

  +---+---+---+
  | A | B | C |
  +---+---+---+

• <expression>:

  +----------+       +------+   +---+---+       +----------+
  |  <var>   | ---> [| "+" | | "-" |] ---> [|  <var>   |]
  +----------+       +------+   +---+---+       +----------+

This diagram shows how the program, statement list, statements, variables, and expressions are structured and connected according to the given EBNF grammar.

2. EBNF and Syntax Graph of FOR statement in Java

The for statement in Java is a control flow statement that allows looping over a block of code for a specific number of times. The general syntax of a for statement is:

for (initialization; condition; update) {
    // statements
}

2.1 EBNF for the for Statement in Java:

Here’s the Extended Backus-Naur Form (EBNF) for the for statement:

<for-statement> ::= "for" "(" <initialization> ";" <condition> ";" <update> ")" <block>

<initialization> ::= <variable-declaration> | <expression> | ""

<condition> ::= <expression> | ""

<update> ::= <expression> | ""

<block> ::= "{" {<statement>} "}"

<statement> ::= <expression> ";" | <for-statement> | <if-statement> | <while-statement> | ...

2.2 Syntax Diagram for the for Statement in Java:

1. <for-statement>:

   • Starts with "for".
   • It includes the initialization, condition, and update parts within parentheses.
   • The loop body is a block (a series of statements enclosed in {}).

2. <initialization>, <condition>, and <update>:

   • These are optional. The initialization typically involves variable declarations or expressions, the condition is an expression, and the update modifies variables.

3. <block>:

   • Represents the body of the loop, which is a sequence of statements enclosed in curly braces {}.

2.3 Corresponding Syntax Graph:

<for-statement>:

+---------+
|   for   |
+---------+
     |
+---+-------------------+---+
| ( | <initialization>   | ) |
+---+-------------------+---+
         |    ;    |    ;    |
+---+   +---+    +---+   +---+
|   |   |<condition>|   |<update>|
|   |               |       |
|   |               v       v
+---+        +----------+  +--------+
            |   <block>  | [ <statement> ]
            +------------+

<initialization>:

+--------------------------+
| <variable-declaration>    |
|          |                |
| <expression>              |
+--------------------------+
      |
     "" (empty allowed)

<condition> and <update>:

+--------------------------+
|      <expression>         |
+--------------------------+
      |
     "" (empty allowed)

<block>:

+-----------+               +------------+
|    {      |   <statement> |    }       |
+-----------+  { <statement>} +------------+

The syntax diagram shows how the for statement in Java consists of the initialization, condition, update expressions, and block of statements, with the parts being optional or empty if needed.