Top: Basic types: string: Operators

#include <ptypes.h>

class string {
    // assignment
    string& operator =(const char*);
    string& operator =(char);
    string& operator =(const string&);
    friend void assign(string&, const char* buf, int len);

    // concatenation
    string& operator +=(const char*);
    string& operator +=(char);
    string& operator +=(const string&);
    string  operator +(const char*) const;
    string  operator +(char) const;
    string  operator +(const string&) const;
    friend  string operator +(const char*, const string&);
    friend  string operator +(char c, const string&);

    // comparison
    bool operator ==(const char*) const;
    bool operator ==(char) const;
    bool operator ==(const string&) const;
    bool operator !=(const char*) const;
    bool operator !=(char c) const;
    bool operator !=(const string&) const;

    // indexed character access, 0-based
    char& string::operator[] (int index);
    const char& string::operator[] (int index) const;
}

The string class defines the following binary operators: assignment (=), concatenation (+), concatenation with assignment (+=) and comparison (==, !=). At least one of the operands (either left or right) must be of type string. Another operand can be one of the following: char, char* or string.

Indexed access operator allows to store or retrieve a value of an individual character. The index is 0-based. When compiled with either DEBUG or CHECK_BOUNDS conditional symbol, bounds checking is performed for the indexed access; if the index is out of bounds (i.e. less than 0 or equals to or greater than the length of the string), an unrecoverable error is raised. The non-debugging version of the library never checks for index overlfows, thus making your program somewhat faster but less safe.

Examples

string s1 = "abc", s2 = 'd', s3;

s3 = s1 + s2;
s2 += "ef";
s3[2] = 'B';

See also: Constructors/destructors, Typecasts, Manipulation, Conversion