char_traits::compare
Compares up to a specified number of characters in two strings.
static int compare(
const char_type* _Str1,
const char_type* _Str2,
size_t _Num
);
Parameters
_Str1
The first of two strings to be compared to each other._Str2
The second of two strings to be compared to each other._Num
The number of elements in the strings to be compared.
Return Value
A negative value if the first string is less than the second string, 0 if the two strings are equal, or a positive value if the first string is greater than the second string.
Remarks
The comparison between the strings is made element by element, first testing for equality and then, if a pair of elements in the sequence tests not equal, they are tested for less than.
If two strings compare equal over a range but one is longer than the other, then the shorter of the two is less than the longer one.
Example
// char_traits_compare.cpp
// compile with: /EHsc
#include <string>
#include <iostream>
int main() {
using namespace std;
char_traits<char>::char_type* s1 = "CAB";
char_traits<char>::char_type* s2 = "ABC";
char_traits<char>::char_type* s3 = "ABC";
char_traits<char>::char_type* s4 = "ABCD";
cout << "The string s1 is: " << s1 << endl;
cout << "The string s2 is: " << s2 << endl;
cout << "The string s3 is: " << s3 << endl;
cout << "The string s4 is: " << s4 << endl;
int comp1, comp2, comp3, comp4;
comp1 = char_traits<char>::compare ( s1 , s2 , 2 );
comp2 = char_traits<char>::compare ( s2 , s3 , 3 );
comp3 = char_traits<char>::compare ( s3 , s4 , 4 );
comp4 = char_traits<char>::compare ( s4 , s3 , 4 );
cout << "compare ( s1 , s2 , 2 ) = " << comp1 << endl;
cout << "compare ( s2 , s3 , 3 ) = " << comp2 << endl;
cout << "compare ( s3 , s4 , 4 ) = " << comp3 << endl;
cout << "compare ( s4 , s3 , 4 ) = " << comp4 << endl;
}
Sample Output
The string s1 is: CAB
The string s2 is: ABC
The string s3 is: ABC
The string s4 is: ABCD
compare ( s1 , s2 , 2 ) = 1
compare ( s2 , s3 , 3 ) = 0
compare ( s3 , s4 , 4 ) = -1
compare ( s4 , s3 , 4 ) = 1
Requirements
Header: <string>
Namespace: std