Stringlist: what changed

Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.

Title: Stringlist

New		Line
1	+	## String list
2	+
3	+	With a string list, a file is read completely into working memory. Stringlist is therefore suitable for files of small and medium size. Stringlist is a way to process files quickly and easily. Stringlist is ideal for processing files that are smaller than 1 megabyte. To process the file, the entire file is loaded into the main memory. Each line of the data record is read into its own array element.
4	+
5	+	## Create a file
6	+
7	+	``` pascal
8	+	procedure SubStringlistFileCreate ();
9	+	var
10	+	// TStringlist is part of the Classes unit
11	+	strList : TStringList;
12	+	begin
13	+	// Creates the string list
14	+	strList := TStringList.Create;
15	+
16	+	// Adds a record including a line break to the string list
17	+	strList.Add('xyz');
18	+
19	+	// Adds a record including a line break to the string list
20	+	strList.Add('abcd');
21	+
22	+	// Writes the string list to a file
23	+	strList.SaveToFile('example.txt');
24	+
25	+	// Releases the string list memory
26	+	strList.Free;
27	+	end;
28	+	```
29	+
30	+	## Append a record to an existing file
31	+
32	+	``` pascal
33	+	procedureSubStringlistApplyFile ();
34	+	var
35	+	// TStringlist is part of the Classes unit
36	+	strList : TStringList;
37	+	begin
38	+	// Creates the string list
39	+	strList := TStringList.Create;
40	+
41	+	// Reads the whole file into the string list
42	+	strList.LoadFromFile('example.txt');
43	+
44	+	// Adds a record including a line break to the string list
45	+	strList.Add('text');
46	+
47	+	// Writes the string list to a file
48	+	strList.SaveToFile('example.txt');
49	+
50	+	// Releases the string list memory
51	+	strList.Free;
52	+	end;
53	+	```
54	+
55	+	## Find a record
56	+
57	+	### Method 1
58	+
59	+	``` pascal
60	+	procedure subStringlistFileSearch ();
61	+	var
62	+	// TStringlist is part of the Classes unit
63	+	strList : TStringList;
64	+	intI : Integer;
65	+	begin
66	+	// Creates the string list
67	+	strList := TStringList.Create;
68	+
69	+	// Reads the whole file into the string list
70	+	strList.LoadFromFile('example.txt');
71	+
72	+	// Use a counting loop to find the corresponding record
73	+	for intI := 0 to strList.Count -1 do
74	+	begin
75	+	// Search and change the record
76	+	if strList [intI] = 'abcd' then
77	+	strList [intI] := 'dcba';
78	+	end;
79	+
80	+	// Writes the string list to a file
81	+	strList.SaveToFile('example.txt');
82	+
83	+	// Releases the string list memory
84	+	strList.Free;
85	+	end;
86	+	```
87	+
88	+	### Method 2
89	+
90	+	``` pascal
91	+	procedure subStringlistInFileSearch2 ();
92	+	var
93	+	// TStringlist is part of the Classes unit
94	+	strList : TStringList;
95	+	intI : Integer;
96	+	begin
97	+	// Creates the string list
98	+	strList := TStringList.Create;
99	+
100	+	// Reads the whole file into the string list
101	+	strList.LoadFromFile('example.txt');
102	+
103	+	// Searches for "Text", if not found, the search returns -1
104	+	intI := strList.IndexOf ('Text');
105	+
106	+	// If found, changes the record
107	+	if intI <> -1 then
108	+	strlist[intI] := 'tXET';
109	+
110	+	// Writes the string list to a file
111	+	strList.SaveToFile('example.txt');
112	+
113	+	// Releases the string list memory
114	+	strList.Free;
115	+	end;
116	+	```
117	+
118	+	## Sort a file alphabetically
119	+
120	+	``` pascal
121	+	procedure SubStringlistFileSort ();
122	+	var
123	+	// TStringlist is part of the Classes unit
124	+	strList : TStringList;
125	+	intI : Integer;
126	+	begin
127	+	// Creates the string list
128	+	strList := TStringList.Create;
129	+
130	+	// Reads the whole file into the string list
131	+	strList.LoadFromFile('example.txt');
132	+
133	+	// Sort the string list alphabetically
134	+	strList.Sort;
135	+
136	+	// Writes the string list to a file
137	+	strList.SaveToFile('example.txt');
138	+
139	+	// Releases the string list memory
140	+	strList.Free;
141	+	end;
142	+	```
143	+
144	+	## See also
145	+
146	+	- [[File types]]
147	+
148	+	---
149	+	From the Free Pascal wiki, page "Stringlist", as it stood on 2020-01-15 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).
150	+	Category: Code Snippets
151	+	Category: FPC
152	+	Category: Pascal

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