The document outlines various string handling functions in programming, focusing on character manipulation and conversion. It includes function prototypes and descriptions for operations such as comparing, copying, concatenating strings, and string searching techniques. The content primarily serves as a reference for programmers working with strings in their code.

1. Introduction ttoo PPrrooggrraammmmiinngg
LLeeccttuurree 1177

2. SSttrriinngg HHaannddlliinngg

3. String Manipulation FFuunnccttiioonnss

4. CChhaarraacctteerr

5. AASSCCIIII

6. 11 bbyyttee == 88 bbiittss

7. EExxaammppllee 11
#iinncclluuddee<<iioossttrreeaamm..hh>>
mmaaiinn (( ))
{{
iinntt ii ;;
cchhaarr cc ;;
ffoorr(( ii == 00;; ii << 225566 ;; ii ++++ ))
{{
cc == ii ;;
ccoouutt <<<< ii <<<< ““tt”” <<<< cc <<<<eennddll ;;
}}
}}

8. HHeeaaddeerr FFiillee
ccttyyppee..hh
#iinncclluuddee<<ccttyyppee..hh>>

9. ccttyyppee FFuunnccttiioonnss
iinntt iissddiiggiitt (( iinntt cc ))
iinntt iissaallpphhaa (( iinntt cc ))
iinntt iissaallnnuumm (( iinntt cc ))
iinntt iissxxddiiggiitt (( iinntt cc ))
iinntt iisslloowweerr (( iinntt cc ))
iinntt iissuuppppeerr (( iinntt cc ))
iinntt ttoolloowweerr (( iinntt cc ))
iinntt ttoouuppppeerr (( iinntt cc ))
iinntt iissssppaaccee (( iinntt cc ))
iinntt iissccnnttrrll (( iinntt cc ))
iinntt iissppuunncctt (( iinntt cc ))
iinntt iisspprriinntt (( iinntt cc ))
iinntt iissggrraapphh (( iinntt cc ))

10. iissddiiggiitt (( )) FFuunnccttiioonn
iinntt iissddiiggiitt (( iinntt cc )) ;;

11. iissaallpphhaa (( )) FFuunnccttiioonn
iinntt iissaallpphhaa (( iinntt cc )) ;;

12. iissaallnnuumm (( )) FFuunnccttiioonn
iinntt iissaallnnuumm (( iinntt cc )) ;;

13. iisslloowweerr (( )) FFuunnccttiioonn
iinntt iisslloowweerr (( iinntt cc )) ;;

14. iissuuppppeerr (( )) FFuunnccttiioonn
iinntt iissuuppppeerr (( iinntt cc )) ;;

15. ttoolloowweerr (( )) FFuunnccttiioonn
iinntt ttoolloowweerr (( iinntt cc )) ;;

16. ttoouuppppeerr (( )) FFuunnccttiioonn
iinntt ttoouuppppeerr (( iinntt cc )) ;;

17. ggeettcchhaarr
(( )) ;;

18. cout << “Please enter a character ssttrriinngg tthheenn pprreessss eenntteerr””;;
wwhhiillee (( (( cc == ggeettcchhaarr (( )) )) !!== ‘‘nn’’ ))
{{
iiff (( iisslloowweerr (( cc )) ))
llcc ++++ ;;
eellssee iiff (( iissuuppppeerr (( cc )) ))
uucc ++++ ;;
eellssee iiff ((iissddiiggiitt (( cc )) ))
ddiigg ++++;;
eellssee iiff (( iissssppaaccee (( cc )) ))
wwss ++++ ;;
eellssee iiff (( iissppuunncctt (( cc )) ))
ppuunn ++++ ;;
eellssee
ootthh ++++ ;;
}}

19. String Conversion FFuunnccttiioonnss
ddoouubbllee aattooff (( cchhaarr ** ssttrr ))
iinntt aattooii ((cchhaarr ** ssttrr ))
lloonngg aattooll ((cchhaarr ** ssttrr ))

20. aattooii (( )) FFuunnccttiioonn
cchhaarr ssttrr [[ ]] ;;
iinntt aaggee ;;
aaggee == aattooii (( ssttrr )) ;;

21. aattooff (( )) FFuunnccttiioonn
1122..8899

22. aattooff (( )) FFuunnccttiioonn
cchhaarr ssttrr [[ ]] ;;
ddoouubbllee ddVVaarr ;;
ddVVaarr == aattooff (( ssttrr )) ;;

23. iinntt mmaaiinn ((iinntt aaggrrcc,, cchhaarr ****aaggrrvv ))
‘‘aarrggcc’’ ssttaannddss ffoorr aa ccoouunntt ooff tthhee nnuummbbeerr ooff
aarrgguummeennttss
‘‘aarrggvv’’ ssttaannddss ffoorr aa vveeccttoorr ooff aarrgguummeennttss

24. SSttrriinngg FFuunnccttiioonnss

25. String Manipulation Functions
Function prototype Function de scription
char *strcpy( char *s1,
const char *s2 )
Copies string s2 into array s1. The value of s1 is
returned.
char *strncpy( char *s1,
const char *s2, size_t n)
Copies at most n characters of string s2 into array s1.
The value of s1 is returned.
int strcmp( const char *s1,
const char *s2 );
Compares string s1 to s2
Returns a negative number if s1 < s2, zero if s1 == s2
or a positive number if s1 > s2
int strncmp( const char *s1,
const char *s2, size_t n );
Compares up to n characters of string s1 to s2
Returns values as above
char *strcat( char *s1,
const char *s2 )
Appends string s2 to array s1. The first character of
s2 overwrites the terminating null character of s1.
The value of s1 is returned.
char *strncat( char *s1,
const char *s2, size_t n )
Appends at most n characters of string s2 to array s1.
The first character of s2 overwrites the terminating
null character of s1. The value of s1 is returned.

26. iinntt ssuumm ;;
iinntt ssuumm__eevveenn ;;
iinntt ssuumm__oodddd ;;
mmyySSttrrccppyy (( )) ;;

27. SSttrriinngg MMaanniippuullaattiioonn
FFuunnccttiioonnss
cchhaarr ** ssttrrccppyy ((cchhaarr **ss11 ,, ccoonnsstt cchhaarr **ss22 )) ;;
cchhaarr ** ssttrrnnccppyy (( cchhaarr **ss11 ,, cchhaarr **ss22 ,, iinntt nn )) ;;
cchhaarr ** ssttrrccaatt ((cchhaarr **ss11 ,, cchhaarr **ss22 )) ;;
cchhaarr ** ssttrrnnccaatt (( cchhaarr **ss11 ,, cchhaarr **ss22 ,, iinntt nn )) ;;

28. ssttrrccmmpp (( ))
FFuunnccttiioonn
iinntt ssttrrccmmpp ((ccoonnsstt cchhaarr **ss11 ,, ccoonnsstt cchhaarr **ss22 )) ;;

29. ssttrrnnccmmpp (( )) FFuunnccttiioonn
iinntt ssttrrnnccmmpp (( ccoonnsstt cchhaarr **ss11 ,, ccoonnsstt cchhaarr **ss22 ,, iinntt nn )) ;;

30. ssttrrlleenn (( )) FFuunnccttiioonn
iinntt ssttrrlleenn (( ccoonnsstt cchhaarr **ss )) ;;

31. SSeeaarrcchh FFuunnccttiioonnss

32. SSeeaarrcchh FFuunnccttiioonnss
Function proto type Function description
char *strchr( const char *s,
int c );
Locates the first occurrence of character c in string s. If c is found, a pointer to c in
s is returned. Otherwise, a NULL pointer is returned.
size_t strcspn( const char
*s1, const char *s2 );
Determines and returns the length of the initial segment of strings 1 consisting of
characters not contained in string s2.
size_t strspn( const char
*s1, const char *s2 );
Determines and returns the length of the initial segment of string s1 consisting only
of characters contained in string s2.
char *strpbrk( const char
*s1, const char *s2 );
Locates the first occurrence in string s1 of any character in string s2. If a character
from string s2 is found, a pointer to the character in string s1 is returned. Other-wise,
a NULL pointer is returned.
char *strrchr( const char *s,
int c );
Locates the last occurrence of c in string s. If c is found, a pointer to c in string s is
returned. Otherwise, a NULL pointer is returned.
char *strstr( const char *s1,
const char *s2 );
Locates the first occurrence in string s1 of string s2. If the string is found, a pointer
to the string in s1 is returned. Otherwise, a NULL pointer is returned.
char *strtok( char *s1, const
char *s2 );
A sequence of calls to strtok breaks string s1 into “tokens”—logical pieces such
as words in a line of text—separated by characters contained in string s2. The first
call contains s1 as the first argument, and subsequent calls to continue tokenizing
the same string contain NULL as the first argument. A pointer to the current token is
returned by each call. If there are no more tokens when the function is calledN, ULL
is returned.

33. TThhiiss iiss aa tteesstt
““ ““ wwrroonngg
‘‘ ‘‘ rriigghhtt
NNUULLLL