06-20-2011, 01:23 PM
TRY 5 Summary
Reading and writing data from/to a file
Step 1. Specifying the location of a file
Step 2. Opening file as a Stream
Step 3. Using methods to read or write data
Step 4. Closing the file
Repeat Expressions
until expression (processing repeats until conditional expression is true)
for expression (specifying a range)
As well as to, there are also the below, downto, and above keywords. The step_size can be omitted when the desired step_size is 1.
for expression (repeats only the values among the elements of a collection, such as an array)
Note that element_variable:Element_type or key key_variable: key_type can be omitted.
Exception Processing
The catch and finally clauses can be omitted. Also, each try can be declared more than once.
Reading and writing data from/to a file
Step 1. Specifying the location of a file
Code:
let location_variable_name:Url = {url “path to file location”}
Step 2. Opening file as a Stream
- TextInputStream (read)
- TextOutputStream (write)
Code:
let stream_variable_name:TextInputStream = {read-open location_variable_name}
let stream_variable_name:TextOutputStream = {write-open location_variable_name}
Step 3. Using methods to read or write data
- Methods such as read-line or write-one-string
Step 4. Closing the file
Code:
{if-non-null stream_variable_name then
{stream_variable_name.close}
}
Repeat Expressions
until expression (processing repeats until conditional expression is true)
Code:
{until conditional_expression do
body
}
for expression (specifying a range)
Code:
{for repeat variable:int = initial_value to final_value step step_size value do
body
}
As well as to, there are also the below, downto, and above keywords. The step_size can be omitted when the desired step_size is 1.
for expression (repeats only the values among the elements of a collection, such as an array)
Code:
{for element_variable:element_type key key_variable[:key type] in (collection) name do
processing
}
Note that element_variable:Element_type or key key_variable: key_type can be omitted.
Exception Processing
Code:
{try
Processing in which an exception may occur.
catch exception_variable_name: exception
Exception Processing
finally
Processing that must be performed regardless of whether an exception occurs
}
The catch and finally clauses can be omitted. Also, each try can be declared more than once.