Substrings

Class string provides member function substrm for retrieving a substring from a string. The result is a new string object that is copied from the source string. Figure 18.3 demonstrates substr.

Figure 18.3. Demonstrating string member function substr.

(This item is displayed on pages 890 - 891 in the print version)

 1 // Fig. 18.3: Fig18_03.cpp
 2 // Demonstrating string member function substr.
 3 #include 
 4 using std::cout;
 5 using std::endl;
 6
 7 #include 
 8 using std::string;
 9
10 int main()
11 {
12 string string1( "The airplane landed on time." );
13
14 // retrieve substring "plane" which
15 // begins at subscript 7 and consists of 5 elements
16 cout << string1.substr( 7, 5 ) << endl;
17 return 0;
18 } // end main

 

 plane

 

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The program declares and initializes a string on line 12. Line 16 uses member function substr to retrieve a substring from string1. The first argument specifies the beginning subscript of the desired substring; the second argument specifies the substring's length.