questions.txt

Please Read: 
 - Chapter 6 Standard Types
 - Review Blocks
 - Chapter 7 Regular Expressions
 - Chapter 22 The Ruby Language: basic types (symbols), variables and constants

1. What is a symbol?

A symbol is a constant name that is guaranteed to be unique and contain the same value through out the entire program. 

2. What is the difference between a symbol and a string?

Symbols are immutable, where as strings are mutable. Symbols are often used as hash keys because they are immutable. 

3. What is a block and how do I call a block?

A block is code between do and end or between brackets. An iterator method can call a block. The format for a block is first you have a collection for the method to iterator over then you have the keyword “do” or a open curly bracket then the value to be passed in, then the code, and finally a closing curly bracket or and “end” keyword.  

4. How do I pass a block to a method? What is the method signature?

By using the keyword yield you can pass a block to a method. You can also pass parameters to a block and a method can receive values from a block using method. The method signature is the method name with the parameter list.   

5. Where would you use regular expressions?

You can use a regular expression to test a string for a matching pattern, to extract a matching pattern from a string, and substitution.