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Since the unit only provides some procedures and functions, there is only one section, which gives the declarations of these functions, together with an explanation.
Attaches Source to Dest and returns Dest.
Program Example11;
Uses strings;
{ Program to demonstrate the StrCat function. }
Const P1 : PChar = 'This is a PChar String.';
Var P2 : PChar;
begin
P2:=StrAlloc (StrLen(P1)*2+1);
StrMove (P2,P1,StrLen(P1)+1); { P2=P1 }
StrCat (P2,P1); { Append P2 once more }
Writeln ('P2 : ',P2);
end.
Compares the null-terminated strings S1 and S2. The result is
Copy the null terminated string in Source to Dest, and returns a pointer to Dest. Dest needs enough room to contain Source, i.e. StrLen(Source)+1 bytes.
Program Example4;
Uses strings;
{ Program to demonstrate the StrCopy function. }
Const P : PCHar = 'This is a PCHAR string.';
var PP : PChar;
begin
PP:=StrAlloc(Strlen(P)+1);
STrCopy (PP,P);
If StrComp (PP,P)<>0 then
Writeln ('Oh-oh problems...')
else
Writeln ('All is well : PP=',PP);
end.
Removes the string in P from the heap and releases the memory.
Program Example17;
Uses strings;
{ Program to demonstrate the StrDispose function. }
Const P1 : PChar = 'This is a PChar string';
var P2 : PChar;
begin
Writeln ('Before StnNew : Memory available : ',MemAvail);
P2:=StrNew (P1);
Writeln ('After StrNew : Memory available : ',MemAvail);
Writeln ('P2 : ',P2);
StrDispose(P2);
Writeln ('After StrDispose : Memory available : ',MemAvail);
end.
Copies the Null-terminated string in Source to Dest, and returns a pointer to the end (i.e. the terminating Null-character) of the copied string.
Program Example6;
Uses strings;
{ Program to demonstrate the StrECopy function. }
Const P : PChar = 'This is a PCHAR string.';
Var PP : PChar;
begin
PP:=StrAlloc (StrLen(P)+1);
If Longint(StrECopy(PP,P))-Longint(PP)<>StrLen(P) then
Writeln('Something is wrong here !')
else
Writeln ('PP= ',PP);
end.
Returns a pointer to the end of P. (i.e. to the terminating null-character.
Program Example6;
Uses strings;
{ Program to demonstrate the StrEnd function. }
Const P : PChar = 'This is a PCHAR string.';
begin
If Longint(StrEnd(P))-Longint(P)<>StrLen(P) then
Writeln('Something is wrong here !')
else
Writeln ('All is well..');
end.
Compares the null-terminated strings S1 and S2, ignoring case. The result is
Program Example8;
Uses strings;
{ Program to demonstrate the StrLComp function. }
Const P1 : PChar = 'This is the first string.';
P2 : PCHar = 'This is the second string.';
Var L : Longint;
begin
Write ('P1 and P2 are ');
If StrComp (P1,P2)<>0 then write ('NOT ');
write ('equal. The first ');
L:=1;
While StrLComp(P1,P2,L)=0 do inc (L);
dec(l);
Writeln (l,' characters are the same.');
end.
Adds MaxLen characters from Source to Dest, and adds a terminating null-character. Returns Dest.
Program Example12;
Uses strings;
{ Program to demonstrate the StrLCat function. }
Const P1 : PChar = '1234567890';
Var P2 : PChar;
begin
P2:=StrAlloc (StrLen(P1)*2+1);
P2^:=#0; { Zero length }
StrCat (P2,P1);
StrLCat (P2,P1,5);
Writeln ('P2 = ',P2);
end.
Compares maximum L characters of the null-terminated strings S1 and S2. The result is
Program Example8;
Uses strings;
{ Program to demonstrate the StrLComp function. }
Const P1 : PChar = 'This is the first string.';
P2 : PCHar = 'This is the second string.';
Var L : Longint;
begin
Write ('P1 and P2 are ');
If StrComp (P1,P2)<>0 then write ('NOT ');
write ('equal. The first ');
L:=1;
While StrLComp(P1,P2,L)=0 do inc (L);
dec(l);
Writeln (l,' characters are the same.');
end.
Copies MaxLen characters from Source to Dest, and makes Dest a null terminated string.
Program Example5;
Uses strings;
{ Program to demonstrate the StrLCopy function. }
Const P : PCHar = '123456789ABCDEF';
var PP : PCHar;
begin
PP:=StrAlloc(11);
Writeln ('First 10 characters of P : ',StrLCopy (PP,P,10));
end.
Returns the length of the null-terminated string P.
Program Example1;
Uses strings;
{ Program to demonstrate the StrLen function. }
Const P : PChar = 'This is a constant pchar string';
begin
Writeln ('P : ',p);
Writeln ('length(P) : ',StrLen(P));
end.
Compares maximum L characters of the null-terminated strings S1 and S2, ignoring case. The result is
Converts P to an all-lowercase string. Returns P.
Program Example14;
Uses strings;
{ Program to demonstrate the StrLower and StrUpper functions. }
Const
P1 : PChar = 'THIS IS AN UPPERCASE PCHAR STRING';
P2 : PChar = 'this is a lowercase string';
begin
Writeln ('Uppercase : ',StrUpper(P2));
StrLower (P1);
Writeln ('Lowercase : ',P1);
end.
Copies MaxLen characters from Source to Dest. No terminating null-character is copied. Returns Dest.
Program Example10;
Uses strings;
{ Program to demonstrate the StrMove function. }
Const P1 : PCHAR = 'This is a pchar string.';
Var P2 : Pchar;
begin
P2:=StrAlloc(StrLen(P1)+1);
StrMove (P2,P1,StrLen(P1)+1); { P2:=P1 }
Writeln ('P2 = ',P2);
end.
Copies P to the Heap, and returns a pointer to the copy.
Program Example16;
Uses strings;
{ Program to demonstrate the StrNew function. }
Const P1 : PChar = 'This is a PChar string';
var P2 : PChar;
begin
P2:=StrNew (P1);
If P1=P2 then
writeln ('This can''t be happening...')
else
writeln ('P2 : ',P2);
end.
Converts a null terminated string in P to a Pascal string, and returns this string. The string is truncated at 255 characters.
Program Example3;
Uses strings;
{ Program to demonstrate the StrPas function. }
Const P : PChar = 'This is a PCHAR string';
var S : string;
begin
S:=StrPas (P);
Writeln ('S : ',S);
end.
Converts the Pascal string in Source to a Null-terminated string, and copies it to Dest. Dest needs enough room to contain the string Source, i.e. Length(Source)+1 bytes.
Program Example2;
Uses strings;
{ Program to demonstrate the StrPCopy function. }
Const S = 'This is a normal string.';
Var P : Pchar;
begin
p:=StrAlloc (length(S)+1);
if StrPCopy (P,S)<>P then
Writeln ('This is impossible !!')
else
writeln (P);
end.
Returns a pointer to the first occurrence of S2 in S1. If S2 does not occur in S1, returns Nil.
Program Example15;
Uses strings;
{ Program to demonstrate the StrPos function. }
Const P : PChar = 'This is a PChar string.';
S : Pchar = 'is';
begin
Writeln ('Position of ''is'' in P : ',longint(StrPos(P,S))-Longint(P));
end.
Returns a pointer to the last occurrence of the character C in the null-terminated string P. If C does not occur, returns Nil.
Returns a pointer to the first occurrence of the character C in the null-terminated string P. If C does not occur, returns Nil.
Program Example13;
Uses strings;
{ Program to demonstrate the StrScan and StrRScan functions. }
Const P : PChar = 'This is a PCHAR string.';
S : Char = 's' ;
begin
Writeln ('P, starting from first ''s'' : ',StrScan(P,s));
Writeln ('P, starting from last ''s'' : ',StrRScan(P,s));
end.
Converts P to an all-uppercase string. Returns P.