Usr bin ruby def test yield end test puts hello world this example is the simplest way to implement a block.
Ruby block comment syntax.
The character set used in the ruby source files for the current implementation is based on ascii.
Puts hello ruby when executed the above program produces the following result hello ruby.
The case of characters in source files is significant.
But if the last argument of a method is preceded by then you can pass a block to this method and this block will be assigned to the last parameter.
All syntactic constructs except identifiers and certain literals may be separated by an arbitrary number of whitespace characters and comments.
Initializing ruby program this is main ruby program terminating ruby program ruby comments.
Comments in ruby begin with a hash mark and continue to the end of the line.
Or a comment may be on the same line after a statement or expression.
The argument names are defined between two pipe characters.
Syntax begin rescue onetypeofexception rescue anothertypeofexception else other exceptions ensure always will be executed end.
A comment hides a line part of a line or several lines from the ruby interpreter.
The character doesn t necessarily have to occur at the beginning of the line.
Any characters from the character to the end of the line are completely ignored by the ruby interpreter.
But there s a special multiline comment syntax.
Here is an example.
You can use block comments to explain more complicated code or code that you don t expect the reader to be familiar with.
It can occur anywhere.
These longer form comments apply to some or all of the.
You call the test block by using the yield statement.
That s what block comments are for.
It looks like this.
Comment syntax and usage.
We enclose the code that could raise an exception in a begin end block and use rescue clauses to tell ruby the types of exceptions we want to handle.
Usr bin ruby w this is a single line comment.
That s exactly how to comment out a block of code in ruby.
Blocks are enclosed in a do end statement or between brackets and they can have multiple arguments.
If you have used each before then you have used blocks.
Ruby blocks are little anonymous functions that can be passed into methods.
You can comment multiple lines using begin and end syntax as follows.