Convert a string to uppercase.
#include <iostream>
#include <cstring>
#include <cctype>
using namespace std;
int main()
{
char str[80];
int i;
strcpy(str, "this is a test");
for(i=0; str[i]; i++) str[i] = toupper(str[i]);
cout << str;
return 0;
}THIS IS A TEST
strcpy, strlen, strcmp, strcat
#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int main()
{
char s1[80], s2[80];
strcpy(s1, "C++");
strcpy(s2, " is power programming.");
cout << "lengths: " << strlen(s1);
cout << " " << strlen(s2) << "\n";
if(!strcmp(s1, s2))
cout << "The strings are equal\n";
else cout << "not equal\n";
strcat(s1, s2);
cout << s1 << "\n";
strcpy(s2, s1);
cout << s1 << " and " << s2 << "\n";
if(!strcmp(s1, s2))
cout << "s1 and s2 are now the same.\n";
return 0;
}lengths: 3 22
not equal
C++ is power programming.
C++ is power programming. and C++ is power programming.
s1 and s2 are now the same.
Using strcat and strncat.
#include <iostream>
using std::cout;
using std::endl;
#include <cstring>
using std::strcat;
using std::strncat;
int main()
{
char s1[ 20 ] = "123456";
char s2[] = "abcdefghi";
char s3[ 40 ] = "";
strcat( s1, s2 );
cout << s1 << "\ns2 = " << s2;
strncat( s3, s1, 6 ); // places "\0" after last character
cout << s1 << "\ns3 = " << s3;
strcat( s3, s1 );
cout << s1 << "\ns3 = " << s3 << endl;
return 0;
}123456abcdefghi
s2 = abcdefghi123456abcdefghi
s3 = 123456123456abcdefghi
s3 = 123456123456abcdefghi
Using strcmp and strncmp
#include <iostream>
using std::cout;
using std::endl;
#include <iomanip>
using std::setw;
#include <cstring>
using std::strcmp;
using std::strncmp;
int main()
{
char *s1 = "abc";
char *s2 = "abC";
char *s3 = "Abc";
cout << "s1 = " << s1 << "\ns2 = " << s2 << "\ns3 = " << s3
<< "\n\nstrcmp(s1, s2) = " << strcmp( s1, s2 )
<< "\nstrcmp(s1, s3) = " << strcmp( s1, s3 )
<< "\nstrcmp(s3, s1) = " << strcmp( s3, s1 );
cout << "\n\nstrncmp(s1, s3, 6) = "
<< strncmp( s1, s3, 2 ) << "\nstrncmp(s1, s3, 7) = "
<< strncmp( s1, s3, 2 ) << "\nstrncmp(s3, s1, 7) = "
<< strncmp( s3, s1, 5 ) << endl;
return 0;
}s1 = abc
s2 = abC
s3 = Abc
strcmp(s1, s2) = 1
strcmp(s1, s3) = 1
strcmp(s3, s1) = -1
strncmp(s1, s3, 6) = 1
strncmp(s1, s3, 7) = 1
strncmp(s3, s1, 7) = -1
Using strcpy()
#include <iostream>
#include <string.h>
int main()
{
char String1[] = "test";
char String2[80];
strcpy(String2,String1);
std::cout << "String1: " << String1 << std::endl;
std::cout << "String2: " << String2 << std::endl;
return 0;
}String1: test
String2: test
Using strlen
#include <iostream>
using std::cout;
using std::endl;
#include <cstring>
using std::strlen;
int main()
{
char *string1 = "asdfasdfasdfasdf";
char *string2 = " f ";
char *string3 = " ";
cout << "The length of \"" << string1 << "\" is " << strlen( string1 )
<< "\nThe length of \"" << string2 << "\" is " << strlen( string2 )
<< "\nThe length of \"" << string3 << "\" is " << strlen( string3 )
<< endl;
return 0;
}The length of "asdfasdfasdfasdf" is 16
The length of " f " is 10
The length of " " is 7
Using strncpy()
#include <iostream>
#include <string.h>
int main()
{
const int MaxLength = 80;
char String1[] = "test";
char String2[MaxLength+1];
strncpy(String2,String1,MaxLength);
String2[strlen(String1)] = "\0"; // add a null to the end
std::cout << "String1: " << String1 << std::endl;
std::cout << "String2: " << String2 << std::endl;
return 0;
}String1: test
String2: test
Using strtok
#include <iostream>
using std::cout;
using std::endl;
#include <cstring>
using std::strtok;
int main()
{
char sentence[] = "a c d e f g e a c d e y gb ";
char *tokenPtr;
tokenPtr = strtok( sentence, " " );
while ( tokenPtr != NULL )
{
cout << tokenPtr << "\n";
tokenPtr = strtok( NULL, " " );
}
return 0;
}a
c
d
e
f
g
e
a
c
d
e
y
gb
