basic_string::compare
執行區分大小寫的比較以指定字串判斷兩個字串是否相等或一個是否小於另一個用於斷字會較少。
int compare(
const basic_string<CharType, Traits, Allocator>& _Str
) const;
int compare(
size_type _Pos1,
size_type _Num1,
const basic_string<CharType, Traits, Allocator>& _Str
) const;
int compare(
size_type _Pos1,
size_type _Num1,
const basic_string<CharType, Traits, Allocator>& _Str,
size_type _Off,
size_type _Count
) const;
int compare(
const value_type* _Ptr
) const;
int compare(
size_type _Pos1,
size_type _Num1,
const value_type* _Ptr
) const;
int compare(
size_type _Pos1,
size_type _Num1,
const value_type* _Ptr
size_type _Num2
) const;
參數
_Str
要與運算元字串比較的字串。_Pos1
比較啟動運算元字串的索引。_Num1
文字方塊的最大字元數從要比較的運算元的字串。_Num2
文字方塊的最大字元數從要比較的參數字串。_Off
比較啟動參數字串的索引。_Count
文字方塊的最大字元數從要比較的參數字串。_Ptr
C 字串運算元字串比較。
傳回值
負值，則此作業會執行不參數字串小於;零，如果兩個字串相等則為，或正數值，如果運算元字串的參數字串大於。
備註
compare 成員函式比較會使用參數和運算元字串全部或部分的。
執行的比較是區分大小寫。
範例
// basic_string_compare.cpp
// compile with: /EHsc
#include <string>
#include <iostream>
int main( )
{
using namespace std;
// The first member function compares
// an operand string to a parameter string
int comp1;
string s1o ( "CAB" );
string s1p ( "CAB" );
cout << "The operand string is: " << s1o << endl;
cout << "The parameter string is: " << s1p << endl;
comp1 = s1o.compare ( s1p );
if ( comp1 < 0 )
cout << "The operand string is less than "
<< "the parameter string." << endl;
else if ( comp1 == 0 )
cout << "The operand string is equal to "
<< "the parameter string." << endl;
else
cout << "The operand string is greater than "
<< "the parameter string." << endl;
cout << endl;
// The second member function compares part of
// an operand string to a parameter string
int comp2a, comp2b;
string s2o ( "AACAB" );
string s2p ( "CAB" );
cout << "The operand string is: " << s2o << endl;
cout << "The parameter string is: " << s2p << endl;
comp2a = s2o.compare ( 2 , 3 , s2p );
if ( comp2a < 0 )
cout << "The last three characters of "
<< "the operand string\n are less than "
<< "the parameter string." << endl;
else if ( comp2a == 0 )
cout << "The last three characters of "
<< "the operand string\n are equal to "
<< "the parameter string." << endl;
else
cout << "The last three characters of "
<< "the operand string\n is greater than "
<< "the parameter string." << endl;
comp2b = s2o.compare ( 0 , 3 , s2p );
if ( comp2b < 0 )
cout << "The first three characters of "
<< "the operand string\n are less than "
<< "the parameter string." << endl;
else if ( comp2b == 0 )
cout << "The first three characters of "
<< "the operand string\n are equal to "
<< "the parameter string." << endl;
else
cout << "The first three characters of "
<< "the operand string\n is greater than "
<< "the parameter string." << endl;
cout << endl;
// The third member function compares part of
// an operand string to part of a parameter string
int comp3a;
string s3o ( "AACAB" );
string s3p ( "DCABD" );
cout << "The operand string is: " << s3o << endl;
cout << "The parameter string is: " << s3p << endl;
comp3a = s3o.compare ( 2 , 3 , s3p , 1 , 3 );
if ( comp3a < 0 )
cout << "The three characters from position 2 of "
<< "the operand string are less than\n "
<< "the 3 characters parameter string "
<< "from position 1." << endl;
else if ( comp3a == 0 )
cout << "The three characters from position 2 of "
<< "the operand string are equal to\n "
<< "the 3 characters parameter string "
<< "from position 1." << endl;
else
cout << "The three characters from position 2 of "
<< "the operand string is greater than\n "
<< "the 3 characters parameter string "
<< "from position 1." << endl;
cout << endl;
// The fourth member function compares
// an operand string to a parameter C-string
int comp4a;
string s4o ( "ABC" );
const char* cs4p = "DEF";
cout << "The operand string is: " << s4o << endl;
cout << "The parameter C-string is: " << cs4p << endl;
comp4a = s4o.compare ( cs4p );
if ( comp4a < 0 )
cout << "The operand string is less than "
<< "the parameter C-string." << endl;
else if ( comp4a == 0 )
cout << "The operand string is equal to "
<< "the parameter C-string." << endl;
else
cout << "The operand string is greater than "
<< "the parameter C-string." << endl;
cout << endl;
// The fifth member function compares part of
// an operand string to a parameter C-string
int comp5a;
string s5o ( "AACAB" );
const char* cs5p = "CAB";
cout << "The operand string is: " << s5o << endl;
cout << "The parameter string is: " << cs5p << endl;
comp5a = s5o.compare ( 2 , 3 , s2p );
if ( comp5a < 0 )
cout << "The last three characters of "
<< "the operand string\n are less than "
<< "the parameter C-string." << endl;
else if ( comp5a == 0 )
cout << "The last three characters of "
<< "the operand string\n are equal to "
<< "the parameter C-string." << endl;
else
cout << "The last three characters of "
<< "the operand string\n is greater than "
<< "the parameter C-string." << endl;
cout << endl;
// The sixth member function compares part of
// an operand string to part of an equal length of
// a parameter C-string
int comp6a;
string s6o ( "AACAB" );
const char* cs6p = "ACAB";
cout << "The operand string is: " << s6o << endl;
cout << "The parameter C-string is: " << cs6p << endl;
comp6a = s6o.compare ( 1 , 3 , cs6p , 3 );
if ( comp6a < 0 )
cout << "The 3 characters from position 1 of "
<< "the operand string are less than\n "
<< "the first 3 characters of the parameter C-string."
<< endl;
else if ( comp6a == 0 )
cout << "The 3 characters from position 2 of "
<< "the operand string are equal to\n "
<< "the first 3 characters of the parameter C-string."
<< endl;
else
cout << "The 3 characters from position 2 of "
<< "the operand string is greater than\n "
<< "the first 3 characters of the parameter C-string."
<< endl;
cout << endl;
}
需求
標題: <string>
命名空間: std