C++/Data Type/Char Array Function

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how to use the strcat function

   
#include <stdio.h>
#include <string.h>
#define iSTRING_SIZE 35
main( )
{
 char greeting[] = "Good morning",
      name[] =" Joe, ",
      message[iSTRING_SIZE];
 strcpy(message,greeting);
 strcat(message,name);
 strcat(message,"how are you?");
 printf("%s\n",message);
 return(0);
}


memchr( ) function: Finding a character in a buffer.

   
#include <string.h>
#include <stdio.h>
char buf[35];
char *ptr;
int main( )
{
 strcpy(buf,"This is a fine day for a search." );
 ptr=(char *)memchr(buf,"f",35);
 if (ptr != NULL)
   printf("character found at location: %d\n",
          ptr-buf+1);
 else
   printf("character not found.\n");
 return (0);
}


memicmp( ) function: compare two string buffers.

   
#include <stdio.h>
#include <string.h>
char buf1[40],buf2[40];
int main( )
{
 strcpy(buf1,"this is a test");
 strcpy(buf2,"this is a test");
 /* 0 - identical strings except for case */
 /* x - any integer, means not identical */
 printf("%d\n",memicmp(buf1,buf2,40));
 /* returns a nonzero value */
 return (0);
}


memset( ) function: set the contents of a string buffer.

   
#include <stdio.h>
#include <string.h>
char buf[20];
int main( )
{
 printf("The contents of buf: %s",memset(buf,"+",15));
 buf[15] = "\0";
 return (0);
}


strchr( ) function: locate the first occurrence of a character in a string.

   
#include <stdio.h>
#include <string.h>
char s1[20] = "What is a friend?";
char *answer;
int main( )
{
 answer=strchr(s1," ");
 printf("After the first blank: %s\n",answer);
 return (0);
}


strcmp( ) function: compare two strings.

   
#include <stdio.h>
#include <string.h>
char s1[45] = "test";
char s2[45] = "another test";
int answer;
  
int main( )
{
 answer = strcmp(s1,s2);
 if (answer>0) 
    printf("s1 is greater than s2");
 else if (answer==0) 
    printf("s1 is equal to s2");
 else 
    printf("s1 is less than s2");
 return (0);
}


strcspn( ) function: find the occurrence of one of a group of characters.

   
#include <stdio.h>
#include <string.h>
char s1[35];
int answer;
int main( )
{
 strcpy(s1,"We are looking for great strings." );
 answer=strcspn(s1,"abc");
 printf("The first a,b,c appeared at position %d\n",answer+1);
 return (0);
}


strlen( ) function: determine the length of a string.

   
#include <stdio.h>
#include <string.h>
char *s1="String length is measured in characters!";
int main( )
{
 printf("The string length is %d",strlen(s1));
 return (0);
}


strstr( ) function: locate a string within a string.

   
#include <stdio.h>
#include <string.h>
int main( )
{
 char *s1="There is always something you miss.";
 char *s2="way";
 printf("%s\n",strstr(s1,s2));
 return (0);
}


strupr( ) function: convert lowercase letters to uppercase.

   
#include <stdio.h>
#include <string.h>
char s1[]="Uppercase characters are easier to read.";
char *s2;
int main( )
{
 s2=strupr(s1);
 printf("The results: %s",s2);
 return (0);
}


uses strncmp to compare two strings with the aid of the strlen function

   
#include <stdio.h>
#include <string.h>
main( )
{
 char s1[]="Adam", s2[]="Abel";
 int istringA_length,iresult=0;
 istringA_length=strlen(s1);
 if (strlen(s2) >= strlen(s1))
   iresult = strncmp(s1,s2,istringA_length);
 printf("The string %s found", iresult == 0 ? "was" : "wasn"t");
 return(0);
}


Using memchr

  
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
   char *s = "This is a string";
   cout << "The remainder of s after character "r" "
        << "is found is \"" << (char *) memchr( s, "r", 16 ) 
        << "\"" << endl;
   return 0;
}


Using memcmp

  
#include <iostream>
#include <iomanip>
#include <string.h>
using namespace std;
int main()
{
   char s1[] = "ABCDEFG", s2[] = "ABCDXYZ";
   cout << "s1 = " << s1 << "\ns2 = " << s2 << endl
        << "\nmemcmp(s1, s2, 4) = " << setw( 3 ) 
        << memcmp( s1, s2, 4 ) << "\nmemcmp(s1, s2, 7) = " 
        << setw( 3 ) << memcmp( s1, s2, 7 )
        << "\nmemcmp(s2, s1, 7) = " << setw( 3 ) 
        << memcmp( s2, s1, 7 ) << endl;
   return 0;
}


Using memcpy

  
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
   char s1[ 17 ], s2[]  = "Copy this string";
   memcpy( s1, s2, 17 );
   cout << "After s2 is copied into s1 with memcpy,\n"
        << "s1 contains \"" << s1 << "\"" << endl;
   return 0;
}


Using memmove

  
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
   char x[] = "this is a test";
   cout << "The string in array x before memmove is: " << x;
   cout << "\nThe string in array x after memmove is:  "
        << (char *) memmove( x, &x[ 5 ], 10 ) << endl;
   return 0;
}


Using memset

  
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
   char string1[ 15 ] = "BBBBBBBBBBBBBB";
   cout << "string1 = " << string1 << endl;
   cout << "string1 after memset = "
        << (char *) memset( string1, "b", 7 ) << endl;
   return 0;
}


Using strerror

  
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
   cout << strerror( 2 ) << endl;
   return 0;
}


Using strpbrk

  
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
   char *string1 = "This is a test";
   char *string2 = "beware";
   cout << "Of the characters in \"" << string2 << "\"\n""
        << *strpbrk( string1, string2 ) << "\""
        << " is the first character to appear in\n\""
        << string1 << "\"" << endl;
   return 0;
}


Using strspn:

  
#include <iostream>
#include <string.h>
using namespace std;
int main()
{
   char *string1 = "The value is 3.14159";
   char *string2 = "test ";
   cout << "string1 = " << string1 
        << "\nstring2 = " << string2
        << "\n\nThe length of the initial segment of string1\n"
        << "containing only characters from string2 = "
        << strspn( string1, string2 ) << endl;
   return 0;
}


using the strcpy function

   
#include <stdio.h>
#include <string.h>
#define iSIZE 20
main( )
{
 char s[iSIZE]="Initialized String!",d[iSIZE];
 strcpy(d,"String Constant");
 printf("%s\n",d);
 strcpy(d,s);
 printf("%s\n",d);
 return(0);
}
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