|
|
| Line 1: |
Line 1: |
| − | {{Warning|All of this is subject to change. Do '''NOT''' use it until its finished. thx}}
| + | Subject to change |
| − | | |
| − | Todo:
| |
| − | Exceptions
| |
| − | Event Notification
| |
| − | Dictionarys with Classes (TObjectDictionary)
| |
| − | | |
| − | ==Basic syntax==
| |
| − | | |
| − | <syntaxhighlight lang="pascal">
| |
| − | {$mode objfpc}
| |
| − | program Example;
| |
| − | | |
| − | uses
| |
| − | Generics.Collections; //import the generics-library of the RTL
| |
| − | | |
| − | type
| |
| − | TStringStringDictionary = specialize TDictionary<string, string>; //specialize a new dictionary and set the desired data-type of key and value
| |
| − | | |
| − | var
| |
| − | MyDictionary : TStringStringDictionary;
| |
| − | begin
| |
| − | MyDictionary := TStringStringDictionary.Create;
| |
| − | try
| |
| − | //do stuff with your dictionary..
| |
| − | finally
| |
| − | MyDictionary.Free;
| |
| − | end;
| |
| − | end.
| |
| − | | |
| − | </syntaxhighlight>
| |
| − | | |
| − | ==Usage:==
| |
| − | | |
| − | <syntaxhighlight lang="pascal">
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | ===Add===
| |
| − | Add Entry or update its current value (key, value)
| |
| − | <syntaxhighlight lang="pascal">
| |
| − | MyDictionary.AddOrSetValue('Key1', 'Value1');
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | There is the Function '''Add'''. But AddOrSetValue is recommended. Add will throw an error if the Key already exists. 'Dublicate Not Allowed in Dictionary' and will not overwrite the value.<br>
| |
| − | | |
| − | | |
| − | ===Remove===
| |
| − | <syntaxhighlight lang="pascal">
| |
| − | MyDictionary.Remove('Key2');
| |
| − | </syntaxhighlight>
| |
| − | If the Key does not exist, no Error is thrown.
| |
| − | ===Clear===
| |
| − | <syntaxhighlight lang="pascal">
| |
| − | MyDictionary.Clear;
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | ===Get Value===
| |
| − | <syntaxhighlight lang="pascal">
| |
| − | WriteLn(MyDictionary.Items['Key1']);
| |
| − | </syntaxhighlight>
| |
| − | If the provided key does not exist, this will throw an Error: 'Dictionary Key does not Exist'. You can use 'TryGetValue' instead.
| |
| − | | |
| − | ===Item Count===
| |
| − | Total number of Items in dictionary (count)
| |
| − | <syntaxhighlight lang="pascal">
| |
| − | WriteLn('Items in Dictionary: ' + IntToStr(MyDictionary.Count));
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | ===Loops===
| |
| − | <syntaxhighlight lang="pascal">
| |
| − | //Loop Keys
| |
| − | for KeyStr in MyDictionary.Keys do
| |
| − | WriteLn('Found key:' + KeyStr);
| |
| − | | |
| − | | |
| − | //Loop Values
| |
| − | for ValueStr in MyDictionary.Values do
| |
| − | WriteLn('Found Value: ' + ValueStr);
| |
| − | | |
| − | | |
| − | //Loop Key-Value-Pairs
| |
| − | //var KeyValuePair : TStringStringDictionary.TDictionaryPair;
| |
| − | for KeyValuePair in MyDictionary do
| |
| − | WriteLn('Found a Pair: Key:' + KeyValuePair.Key + ' Value:' + KeyValuePair.Value);
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | ===Check If Key/Value Exists===
| |
| − | | |
| − | <syntaxhighlight lang="pascal">
| |
| − | //Check if Key exists
| |
| − | if MyDictionary.ContainsKey('Key1') then
| |
| − | WriteLn('key exists')
| |
| − | else
| |
| − | WriteLn('key not found');
| |
| − | | |
| − | | |
| − | //Check if Value exists
| |
| − | if MyDictionary.ContainsValue("Searched value") then
| |
| − | writeln('value exists')
| |
| − | else
| |
| − | writeln('value not found');
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | | |
| − | ===Trying===
| |
| − | If you want to get a feedback, then use these functions. They return a boolean.<br>
| |
| − | True if sucessfull, False if not. No Error is thrown, so they are a good alternative to GetValue or Add.
| |
| − | | |
| − | ====TryAdd====
| |
| − | TryAdd returns True if added successfully, False otherwise.
| |
| − | <syntaxhighlight lang="pascal">
| |
| − | if MyDictionary.TryAdd('Key','TestValue') then
| |
| − | writeln('added successfully')
| |
| − | else
| |
| − | writeln('not sucessfull');
| |
| − | </syntaxhighlight>
| |
| − | TryAdd does not work when you try to update a existing keys value. Use AddOrSetValue instead.
| |
| − | ====TryGetValue====
| |
| − | TryGetValue takes two Arguments ->(key, value) and returns a '''boolean'''.<br>
| |
| − | If found, it returns '''True''' and the provided 'value' variable becomes the value of the searched KeyValuePair.<br>
| |
| − | If not found,the function returns '''False''' and the provided 'value'-variable is empty or nill.
| |
| − | | |
| − | <syntaxhighlight lang="pascal">
| |
| − | | |
| − | if MyDictionary.TryGetValue('Key', SearchedValue) then
| |
| − | WriteLn('Key found. Its value is: ' + SearchedValue)
| |
| − | else
| |
| − | WriteLn('Could not get value');
| |
| − | | |
| − | //writeln(BoolToStr(MyDictionary.TryGetValue('Key', SearchedValue)));
| |
| − | </syntaxhighlight>
| |
| − | | |
| − | | |
| − | | |
| − | | |
| − | ==Source Code==
| |
| − | | |
| − | | |
| − | <syntaxhighlight lang="pascal">
| |
| − | | |
| − | {$mode objfpc}
| |
| − | | |
| − | program Example;
| |
| − | | |
| − | uses
| |
| − | Generics.Collections //import the generics-library of the RTL
| |
| − | | |
| − | type
| |
| − | | |
| − | TStringStringDictionary = specialize TDictionary<string, string>; //specialize a new dictionary and set the data-type of key and value
| |
| − | | |
| − | var
| |
| − | MyDictionary : TStringStringDictionary;
| |
| − | TestClass : TmyCoolClass;
| |
| − | //
| |
| − | KeyString: string;
| |
| − | KeyValuePair : TStringStringDictionary.TDictionaryPair;
| |
| − | SearchedValue : string;
| |
| − | begin
| |
| − | | |
| − | //create the dictionary
| |
| − | MyDictionary := TStringStringDictionary.Create;
| |
| − | | |
| − | //Add Element or update its value to new (key, value)
| |
| − | MyDictionary.AddOrSetValue('Key1', 'Value1');
| |
| − | | |
| − | //Remove Element
| |
| − | MyDictionary.AddOrSetValue('Key2', 'Another Value');
| |
| − | MyDictionary.Remove('Key2');
| |
| − | | |
| − | | |
| − | //Clear entire dictionary
| |
| − | MyDictionary.Clear;
| |
| − | | |
| − | // Total number of Items in dictionary (count)
| |
| − | writeln('Items in Dictionary: ' + IntToStr(MyDictionary.Count));
| |
| − | | |
| − | //Get Value by Key
| |
| − | writeln(MyDictionary.Items['Key1'].Name); //If the provided key does not exist, this will throw a Error :'Dictionary Key does not Exist'
| |
| − | | |
| − | | |
| − | //----------------------Trying------------------
| |
| − | | |
| − | | |
| − | //TryAdd returns True if added successfully, False otherwise
| |
| − | writeln('TryAdd: ' + BoolToStr(MyDictionary.TryAdd('Key2',TestClass ),'True', 'False'));
| |
| − | | |
| − | //'TryGetValue'takes two Arguments ->(key, value) and returns a boolean.
| |
| − | //If found, it returns true and the provided 'value' variable becomes the value of the searched KeyValuePair
| |
| − | //if not found,the function returns False and the provided 'value'-variable is nil
| |
| − | writeln(BoolToStr(MyDictionary.TryGetValue('Key', SearchedValue)));
| |
| − | if MyDictionary.TryGetValue('Key', SearchedValue) then
| |
| − | writeln('Key found. Its Value is ' + SearchedValue.Name )
| |
| − | else
| |
| − | if SearchedValue = Nil then
| |
| − | writeln('the provided Value is Nil now');
| |
| − | | |
| − | | |
| − | //----------------------Loop through the Dictionary------------------
| |
| − | | |
| − | //Loop Keys
| |
| − | for KeyString in MyDictionary.Keys do
| |
| − | writeln('Found key:' + KeyString);
| |
| − | | |
| − | | |
| − | //Loop Values
| |
| − | for ValueStr in MyDictionary.Values do
| |
| − | writeln('Found Value:' + ValueStr);
| |
| − | | |
| − | | |
| − | //Loop Key-Value-Pairs
| |
| − | for KeyValuePair in MyDictionary do
| |
| − | writeln('Found a Pair: Key:' + KeyValuePair.Key + ' Value:' + KeyValuePair.Value.Name);
| |
| − | | |
| − | | |
| − | | |
| − | //----------------------Check if.. exists in whole Dictionary------------------
| |
| − | | |
| − | //Check if Key exists
| |
| − | if MyDictionary.ContainsKey('Key1') then
| |
| − | writeln('key exists')
| |
| − | else
| |
| − | writeln('key not found');
| |
| − | | |
| − | | |
| − | //Check if Value exists
| |
| − | if MyDictionary.ContainsValue(TestClass) then
| |
| − | writeln('value exists')
| |
| − | else
| |
| − | writeln('value not found');
| |
| − | | |
| − | | |
| − | readln() //for Windows-console-users
| |
| − | end.
| |
| − | | |
| − | | |
| − | | |
| − | </syntaxhighlight>
| |
