Difference between revisions of "Basic Pascal Tutorial/Chapter 5/Records"
From Lazarus wiki
Jump to navigationJump to searchm (Text replace - "delphi>" to "syntaxhighlight>") |
|||
| Line 4: | Line 4: | ||
To declare a record, you'd use: | To declare a record, you'd use: | ||
| − | < | + | <syntaxhighlight> |
TYPE | TYPE | ||
TypeName = record | TypeName = record | ||
| Line 11: | Line 11: | ||
identifierlistn : datatypen; | identifierlistn : datatypen; | ||
end; | end; | ||
| − | </ | + | </syntaxhighlight> |
For example: | For example: | ||
| − | < | + | <syntaxhighlight> |
type | type | ||
InfoType = record | InfoType = record | ||
| Line 22: | Line 22: | ||
Zip : integer; | Zip : integer; | ||
end; | end; | ||
| − | </ | + | </syntaxhighlight> |
Each of the identifiers <tt>Name, Age, City, State</tt>, and <tt>Zip</tt> are referred to as fields. You access a field within a variable by: | Each of the identifiers <tt>Name, Age, City, State</tt>, and <tt>Zip</tt> are referred to as fields. You access a field within a variable by: | ||
| − | < | + | <syntaxhighlight> |
VariableIdentifier.FieldIdentifier | VariableIdentifier.FieldIdentifier | ||
| − | </ | + | </syntaxhighlight> |
A period separates the variable and the field name. | A period separates the variable and the field name. | ||
There's a very useful statement for dealing with records. If you are going to be using one record variable for a long time and don't feel like typing the variable name over and over, you can strip off the variable name and use only field identifiers. You do this by: | There's a very useful statement for dealing with records. If you are going to be using one record variable for a long time and don't feel like typing the variable name over and over, you can strip off the variable name and use only field identifiers. You do this by: | ||
| − | < | + | <syntaxhighlight> |
WITH RecordVariable DO | WITH RecordVariable DO | ||
BEGIN | BEGIN | ||
... | ... | ||
END; | END; | ||
| − | </ | + | </syntaxhighlight> |
Example: | Example: | ||
| − | < | + | <syntaxhighlight> |
with Info do | with Info do | ||
begin | begin | ||
| Line 46: | Line 46: | ||
ZIP := 90210; | ZIP := 90210; | ||
end; | end; | ||
| − | </ | + | </syntaxhighlight> |
{|style=color-backgroud="white" cellspacing="20" | {|style=color-backgroud="white" cellspacing="20" | ||
Revision as of 15:54, 24 March 2012
5E - Records (author: Tao Yue, state: unchanged)
A record allows you to keep related data items in one structure. If you want information about a person, you may want to know name, age, city, state, and zip.
To declare a record, you'd use:
TYPE
TypeName = record
identifierlist1 : datatype1;
...
identifierlistn : datatypen;
end;For example:
type
InfoType = record
Name : string;
Age : integer;
City, State : String;
Zip : integer;
end;Each of the identifiers Name, Age, City, State, and Zip are referred to as fields. You access a field within a variable by:
VariableIdentifier.FieldIdentifierA period separates the variable and the field name.
There's a very useful statement for dealing with records. If you are going to be using one record variable for a long time and don't feel like typing the variable name over and over, you can strip off the variable name and use only field identifiers. You do this by:
WITH RecordVariable DO
BEGIN
...
END;Example:
with Info do
begin
Age := 18;
ZIP := 90210;
end;| previous | contents | next |
