Frequently Used string functions

Function quotedstr (const S: string): string; $ [sysutils. Pas
Returns the expression of string s in Pascal.
It indicates that one of the single quotes will be converted into two
See procedure system. insert
Example edit2.text: = quotedstr (edit1.text );
When there are too many threads, there are too many threads, too many threads.
Function ansiquotedstr (const S: string; quote: Char): string; $ [sysutils. Pas
Function returns the expression of string s in quotation marks
Description: ansiquotedstr ('Hello "world', '@') = '@ hello" World @'; ansiquotedstr ('Hello "world ','"') = '"hello" "world "'
Refer to function sysutils. ansistrscan
Example edit2.text: = ansiquotedstr (edit1.text ,'"');
When there are too many threads, there are too many threads, too many threads.
Function ifthen (avalue: Boolean; const atrue: string; afalse: String = ''): string; overload; $ [strutils. Pas
Function returns the specified logical string
Ifthen (true, 'yes', 'no') = 'yes'; ifthen (false, 'yes', 'no') = 'no'
See <null>
Example edit3.text: = ifthen (checkbox1.checked, edit1.text, edit2.text );
When there are too many threads, there are too many threads, too many threads.
First function leftstr (const atext: string; const acount: integer): string; $ [strutils. Pas
Function returns the acount characters on the left of the atext string.
Description leftstr ('20140901', 3) = '20160901'
Refer to function system. Copy
Example edit3.text: = leftstr (edit1.text, spinedit1.value );
When there are too many threads, there are too many threads, too many threads.
First function rightstr (const atext: string; const acount: integer): string; $ [strutils. Pas
Function returns the acount characters on the right of the atext string.
Description: rightstr ('20140901', 3) = '20160901'
Refer to function system. Copy
Example edit3.text: = rightstr (edit1.text, spinedit1.value );
When there are too many threads, there are too many threads, too many threads.
First function midstr (const atext: string; const astart, acount: integer): string; $ [strutils. Pas
Returns the acount characters starting with astart.
It means copy.
Refer to function system. Copy
Example edit3.text: = midstr (edit1.text, spinedit1.value, spinedit2.value );

When there are too many threads, there are too many threads, too many threads.
Function ansimatchstr (const atext: string; const avalues: array of string): Boolean; $ [strutils. Pas
Function returns whether the avalues array contains the atext string.
Case Sensitive
Refer to function strutils. ansiindexstr
Example: checkbox1.checked: = ansimatchstr (edit1.text, ['a1', 'a2 ', 'a3', 'a4']);
When there are too many threads, there are too many threads, too many threads.
First function ansiindexstr (const atext: string; const avalues: array of string): integer; $ [strutils. Pas
Returns the position of the string atext in the string array avalues.
Case Sensitive
Refer to function sysutils. ansisamestr
Example: spinedit1.value: = ansiindexstr (edit1.text, ['a1', 'a2 ', 'a3', 'a4 ']);
When there are too many threads, there are too many threads, too many threads.
First function dupestring (const atext: string; acount: integer): string; $ [strutils. Pas
Returns the acount duplicate of the atext string.
Indicates that ''is returned when acount is 0''
Refer to function system. setlength
Example edit3.text: = dupestring (edit1.text, spinedit1.value );
When there are too many threads, there are too many threads, too many threads.
First function reversestring (const atext: string): string; $ [strutils. Pas
Returns the reverse order of the string atext.
Description reversestring ('20140901') = '20160901'
Refer to function system. setlength
Example edit3.text: = reversestring (edit1.text );
When there are too many threads, there are too many threads, too many threads.
First function stuffstring (const atext: string; astart, alength: Cardinal; const asubtext: string): string; $ [strutils. Pas
Function returns nested strings
Description: astart: nesting start position; alength: Nested length; stuffstring ('abcd', 2, 0, '12') = 'a12bcd'
Refer to function system. Copy
Example edit3.text: = stuffstring (edit1.text, spinedit1.value, spinedit2.value, edit2.text );
When there are too many threads, there are too many threads, too many threads.
First function randomfrom (const avalues: array of string): string; overload; $ [strutils. Pas
Function returns an element of the string array avalues at random.
Randomize is recommended.
Refer to function system. Random
Example randomize; edit3.text: = randomfrom (['a1', 'a2 ', 'a3', 'a4 ']);
When there are too many threads, there are too many threads, too many threads.
Function adjustlinebreaks (const S: string; style: ttextlinebreakstyle ={$ ifdef Linux} tlbslf {$ endif }{$ ifdef mswindows} tlbscrlf {$ endif}): string; $ [sysutils. PAS
Function returns the line delimiter of the given string to the CR/LF sequence.
Description: adjustlinebreaks ('1' #13 '2' #13) = '1' #13 #10 '2' #13 #10; adjustlinebreaks ('1' # 10' 2' #10) = '1' #13 # 10' 2' #13 #10
Refer to function sysutils. strnextchar

too many parameters have been written before using the function Format (const format: string; const ARGs: array of const): string; $ [sysutils. the PAS
function returns the character format of formatting an array constant in the specified way.
this function is the most used function in Delphi, here are a few examples to give you an intuitive understanding
"%" [Index ":"] ["-"] [width] [". "Abstract] type
Format ('X = % d', [12]); // 'X = 12' // The most common
Format ('X = % 3d ', [12]); // 'X = 12' // specify the width
Format ('X = % F', [12.0]); // 'X = 12.00 '// floating point number
Format ('X = %. 3f', [12.0]); // 'X = 100' // specify the decimal point
Format ('X = %. * F', [5, 12.0]); // 'X = 100' // dynamic configuration
Format ('X = %. 5D ', [12]); // 'X = 100' // Add 0
Format ('X = %. 5x ', [12]); // 'X = 20.c' // hexadecimal
Format ('X = % 1: d % 0: d ', [12, 13]); // 'X = 100' // use the index
Format ('X = % P', [nil]); // 'X = 100' // pointer
Format ('X = % 1.1e ', [00000000]); // 'X = 1.2e + 001' // scientific note
Format ('X = % ', []); // 'X = % '// get "%"
S: = format (' % S % d', [s, I]); // S: = S + strtoint (I); // connection string
refer to proceduer sysutils. fmtstr
example edit1.text: = format (edit2.text, [strtofloatdef (edit.3.text, 0)]);