Operation of String in C + +

1. Initialization of strings and reading

int main () {    string s1= "AAA";    String s2= "BBB";    string s3=s1;   Consider the constructor    string S4 (' a ');  Initialize to "aaaaaaaaaa"    cout<<s1<<endl;    cout<<s2<<endl;    cout<<s3<<endl;    cout<<s4<<endl;    cout<< "Iterator method" <<endl;    for (String::iterator it = S1.begin (); It! = S1.end (); it++) {        cout<< *it << ""    ;    } cout<< "\nat method Take element" <<endl;    Use the at FETCH element for    (int i=0; i<s1.length (); i++) {        cout<<s1.at (i) << "  ";   Use at to throw an exception    }    return 0;}

2, get the first address of the string, copy, connect operation

int main () {    string s= "ABCD";    printf ("%s\n", S.c_str ());   Get the first address of the string    //Copy the contents of S into buf    char buf[128]={0};  Initializes a null value of    s.copy (buf,3,0);    cout<< "BUF:" <<buf<<endl;    Connection string    s1= "AAA";    String s2= "BBB";    string ss=s1+s2;    String s3= "1111";    String s4= "2222";    S3.append (S4);    cout<< "SS:" <<ss<<endl;    cout<< "S3:" <<s3<<endl;    return 0;}

3. String lookup and substitution operations

int main () {    ///String lookup and substitution strings    s= "Hello, just enjoy the World,hello, just enjoy the World.hello, just enjoy the Wo Rld. ";    int Index=s.find ("Hello", 0);    Start looking for    cout<< "index:" from 0 position <<index<<endl;    The number of times to ask Hello to appear    int cindex=s.find ("Hello", 0);    while (cindex! = string::npos) {        cout<< "CIndex:" <<cindex<<endl;        S.replace (cindex,5, "HELLO");    The replace operation starts with the CIndex, replacing the 5 characters with "Hello"        cindex=s.find ("Hello", cindex+1);    }    cout<<s<<endl;    return 0;}

4. Delete operation of string

int main () {    string s= "Hello, world,i hello am Hello walking on Hello the";    String::iterator it = Find (S.begin (), S.end (), ' l ');    if (it = S.end ()) {        s.erase (it);    }    The result of cout<< "s deletion is:" <<s<<endl;    Specifies the continuous location to remove    s.erase (S.begin () +7,s.begin () +15);    cout<< "Second Delete:" <<s<<endl;    String s2= "Afghi";    S2.insert (1, "BCDE");    cout<< "S2:" <<s2<<endl;    return 0;}

5. Application of Transform in string

The std::transform applies to the given operation within the specified range and stores the result in another specified range. To use the Std::transform function you need to include the <algorithm> header file.

int main () {    string s1= "aaaabbbbccccdddd";    /* Transform (B1,E1,B2,OP)      //Convert the data in an interval [b1,e1] into a second container     * Plus: Reason * The problem is the     version of Std::tolower inherited from the C standard library was a non-template function,     * But there was other  versions O  F std::tolower that is function templates,     * and it's possible for them to being included depending on the standard  Library implementation.     * You  actually want to use the Non-template function,     * But there are ambiguity when just tolower is provided as The predicate.     * Translation come to say, both C version of the Toupper/tolower function, and STL template function Toupper/tolower, there are conflicts.     *    /transform (S1.begin (), S1.end (), S1.begin (),:: ToUpper);    cout<<s1<<endl;    return 0;}

Operation of String in C + +