JavaScript 2.0 Core Language Statements

Thursday, November 11, 1999

Most of the behavior of statements is the same as in JavaScript 1.5. Differences are highlighted below.

Empty Statement

Expression Statement

Block

Boxes

A box has the syntax:

A box behaves like a regular block except that it forms its own scope. Variable and function definitions without a Visibility prefix inside the box belong to that box instead of the global scope or the enclosing function, class, or box.

Visibility-Specifying Blocks

A block can be annotated with a Visibility prefix as follows:

Such a block behaves like a regular block except that every declaration inside that block (but not inside any enclosed function, class, box, or nested visibility-specifying block) that does not have an explicit Visibility prefix uses the Visibility prefix given by the block.

Visibility-specifying blocks are useful to define several items without having to repeat a Visibility prefix for each one. For example,

class foo {
  field z:integer;
  public field a;
  private field b;
  public method f() {}
  public method g(x:integer) {}
}

is equivalent to:

class foo {
  field z:integer;
  public {
    field a;
    private field b;
    method f() {}
    method g(x:integer) {}
  }
}

Labeled Statements

If Statement

The semicolon is optional before the else.

Switch Statement

Do-While Statement

The semicolon is optional before the closing while.

While Statement

For Statements

With Statement

Continue and Break Statements

Return Statement

Throw Statement

Try Statement

Programs

Waldemar Horwat Last modified Thursday, November 11, 1999