1. Chapter 15 - Class string and String Stream Processing
Outline
Introduction
string Assignment and Concatenation
Comparing strings
Substrings
Swapping strings
string Characteristics
Finding Strings and Characters in a string
Replacing Characters in a string
Inserting Characters into a string
Conversion to C-Style char * Strings
Iterators
String Stream Processing

2. Template class basic_string
Introduction
Template class basic_string
String manipulation (copying, searching, etc.)
typedef basic_string< char > string;
Also typedef for wchar_t
Include <string>
string initialization
string s1( "Hello" );
string s2( 8, 'x' );
8 'x' characters
string month = "March"
Implicitly calls constructor

3. No conversion from int or char
Introduction
No conversion from int or char
The following definitions are errors
string error1 = 'c';
string error2( 'u' );
string error3 = 22;
string error4( 8 );
However, can assign to one char if declared
s = 'n';

4. 15.1 Introduction string features Not necessarily null terminated
length member function: s1.length()
Use [] to access individual characters: s1[0]
0 to length-1
string not a pointer
Many member functions take start position and length
If length argument too large, max chosen
Stream extraction
cin >> stringObject;
getline( cin, s)
Delimited by newline

5. 15.2 string Assignment and Concatenation
Makes a separate copy
s2.assign(s1);
Same as s2 = s1;
myString.assign(s, start, N);
Copies N characters from s, beginning at index start
Individual characters
s2[0] = s3[2];

6. 15.2 string Assignment and Concatenation
Range checking
s3.at( index );
Returns character at index
Can throw out_of_range exception
[] has no range checking
Concatenation
s3.append( "pet" );
s3 += "pet";
Both add "pet" to end of s3
s3.append( s1, start, N );
Appends N characters from s1, beginning at index start

7. String initialization and assignment.
// Fig. 15.1: fig15_01.cpp
// Demonstrating string assignment and concatenation.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string string1( "cat" );
string string2;
string string3; 17
string2 = string1; // assign string1 to string2
string3.assign( string1 ); // assign string1 to string3
cout << "string1: " << string1 << "\nstring2: " << string2
<< "\nstring3: " << string3 << "\n\n"; 22
fig15_01.cpp (1 of 3)
String initialization and assignment.
Output
string1: cat
string2: cat
string3: cat

8. Note use of member function at instead of [].
// modify string2 and string3
string2[ 0 ] = string3[ 2 ] = 'r'; 25
cout << "After modification of string2 and string3:\n"
<< "string1: " << string1 << "\nstring2: " << string2
<< "\nstring3: "; 29
// demonstrating member function at
for ( int i = 0; i < string3.length(); i++ )
cout << string3.at( i ); 33
// declare string4 and string5
string string4( string1 + "apult" );
string string5; 37
// overloaded +=
string3 += "pet"; // create "carpet"
string1.append( "acomb" ); // create "catacomb" 41
// append subscript locations 4 through end of string1 to
// create string "comb" (string5 was initially empty)
string5.append( string1, 4, string1.length() ); 45
cout << "\n\nAfter concatenation:\nstring1: " << string1
<< "\nstring2: " << string2 << "\nstring3: "
<< string3 << "\nstring4: " << string4
<< "\nstring5: " << string5 << endl; 50
fig15_01.cpp (2 of 3)
After modification of string2 and string3:
string1: cat
string2: rat
string3: car
Note use of member function at instead of [].
After concatenation:
string1: catacomb
string2: rat
string3: carpet
string4: catapult
string5: comb

9. fig15_01.cpp (3 of 3) fig15_01.cpp output (1 of 1)
return 0; 52
53 } // end main
string1: cat
string2: cat
string3: cat
After modification of string2 and string3:
string2: rat
string3: car
After concatenation:
string1: catacomb
string3: carpet
string4: catapult
string5: comb
fig15_01.cpp (3 of 3) fig15_01.cpp output (1 of 1)

10. 15.3 Comparing strings Overloaded operators s1.compare(s2)
==, !=, <, >, <= and >=
Return bool
s1.compare(s2)
Returns positive if s1 lexicographically greater
Compares letter by letter
'B' lexicographically greater than 'A'
Returns negative if less, zero if equal
s1.compare(start, length, s2, start, length)
Compare portions of s1 and s2
s1.compare(start, length, s2)
Compare portion of s1 with all of s2

11. fig15_02.cpp (1 of 4) 1 // Fig. 15.2: fig15_02.cpp
// Demonstrating string comparison capabilities.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string string1( "Testing the comparison functions." );
string string2( "Hello" );
string string3( "stinger" );
string string4( string2 ); 18
fig15_02.cpp (1 of 4)

12. Note use of overloaded == operator. fig15_02.cpp (2 of 4)
cout << "string1: " << string1 << "\nstring2: " << string2
<< "\nstring3: " << string3 << "\nstring4: " << string4
<< "\n\n"; 22
// comparing string1 and string4
if ( string1 == string4 )
cout << "string1 == string4\n";
else { // string1 != string4
if ( string1 > string4 )
cout << "string1 > string4\n";
else // string1 < string4
cout << "string1 < string4\n"; } 32
// comparing string1 and string2
int result = string1.compare( string2 ); 35
if ( result == 0 )
cout << "string1.compare( string2 ) == 0\n";
else // result != 0
if ( result > 0 )
cout << "string1.compare( string2 ) > 0\n";
else // result < 0
cout << "string1.compare( string2 ) < 0\n"; 43
Note use of overloaded == operator.
fig15_02.cpp (2 of 4)
string1: Testing the comparison functions.
string2: Hello
string3: stinger
string4: Hello
string1 > string4

13. Note use of compare. fig15_02.cpp (3 of 4)
// comparing string1 (elements 2-5) and string3 (elements 0-5)
result = string1.compare( 2, 5, string3, 0, 5 ); 46
if ( result == 0 )
cout << "string1.compare( 2, 5, string3, 0, 5 ) == 0\n";
else // result != 0
if ( result > 0 )
cout << "string1.compare( 2, 5, string3, 0, 5 ) > 0\n";
else // result < 0
cout << "string1.compare( 2, 5, string3, 0, 5 ) < 0\n"; 54
// comparing string2 and string4
result = string4.compare( 0, string2.length(), string2 ); 57
if ( result == 0 )
cout << "string4.compare( 0, string2.length(), "
<< "string2 ) == 0" << endl;
else // result != 0
if ( result > 0 )
cout << "string4.compare( 0, string2.length(), "
<< "string2 ) > 0" << endl;
else // result < 0
cout << "string4.compare( 0, string2.length(), "
<< "string2 ) < 0" << endl; 68
Note use of compare.
fig15_02.cpp (3 of 4)

14. fig15_02.cpp (4 of 4) fig15_02.cpp output (1 of 1)
// comparing string2 and string4
result = string2.compare( 0, 3, string4 ); 71
if ( result == 0 )
cout << "string2.compare( 0, 3, string4 ) == 0" << endl;
else // result != 0
if ( result > 0 )
cout << "string2.compare( 0, 3, string4 ) > 0" << endl;
else // result < 0
cout << "string2.compare( 0, 3, string4 ) < 0" << endl; 79
return 0; 81
82 } // end main
fig15_02.cpp (4 of 4) fig15_02.cpp output (1 of 1)
string1: Testing the comparison functions.
string2: Hello
string3: stinger
string4: Hello
string1 > string4
string1.compare( string2 ) > 0
string1.compare( 2, 5, string3, 0, 5 ) == 0
string4.compare( 0, string2.length(), string2 ) == 0
string2.compare( 0, 3, string4 ) < 0

15. Function substr gets substring
Substrings
Function substr gets substring
s1.substr( start, N );
Gets N characters, beginning with index start
Returns substring

16. fig15_03.cpp (1 of 1) fig15_03.cpp output (1 of 1)
// Fig. 15.3: fig15_03.cpp
// Demonstrating string member function substr.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string string1( "The airplane landed on time." ); 15
// retrieve substring "plane" which
// begins at subscript 7 and consists of 5 elements
cout << string1.substr( 7, 5 ) << endl; 19
return 0; 21
22 } // end main
fig15_03.cpp (1 of 1) fig15_03.cpp output (1 of 1)
Note usage of substr.
plane

17. Swapping strings
s1.swap(s2);
Switch contents of two strings

18. fig15_04.cpp (1 of 1) Call swap. 1 // Fig. 15.4: fig15_04.cpp
// Using the swap function to swap two strings.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string first( "one" );
string second( "two" ); 16
// output strings
cout << "Before swap:\n first: " << first
<< "\nsecond: " << second; 20
first.swap( second ); // swap strings 22
cout << "\n\nAfter swap:\n first: " << first
<< "\nsecond: " << second << endl; 25
return 0; 27
28 } // end main
fig15_04.cpp (1 of 1)
Call swap.

19. Before swap: first: one second: two After swap: first: two second: one
After swap:
first: two
second: one
fig15_04.cpp output (1 of 1)

20. 15.6 string Characteristics
Member functions
s1.size() and s1.length()
Number of characters in string
s1.capacity()
Number of elements that can be stored without reallocation
s1.max_size()
Maximum possible string size
s1.empty()
Returns true if empty
s1.resize(newlength)
Resizes string to newlength

21. fig15_05.cpp (1 of 3) 1 // Fig. 15.5: fig15_05.cpp
// Demonstrating member functions related to size and capacity.
#include <iostream> 4
using std::cout;
using std::endl;
using std::cin;
using std::boolalpha; 9
10 #include <string> 11
12 using std::string; 13
14 void printStatistics( const string & ); 15
16 int main()
17 {
string string1; 19
cout << "Statistics before input:\n" << boolalpha;
printStatistics( string1 ); 22
// read in "tomato"
cout << "\n\nEnter a string: ";
cin >> string1; // delimited by whitespace
cout << "The string entered was: " << string1;
fig15_05.cpp (1 of 3)

22. fig15_05.cpp (2 of 3) Resize string. 27
cout << "\nStatistics after input:\n";
printStatistics( string1 ); 30
// read in "soup"
cin >> string1; // delimited by whitespace
cout << "\n\nThe remaining string is: " << string1 << endl;
printStatistics( string1 ); 35
// append 46 characters to string1
string1 += " abcdefghijklmnopqrstuvwxyz ";
cout << "\n\nstring1 is now: " << string1 << endl;
printStatistics( string1 ); 40
// add 10 elements to string1
string1.resize( string1.length() + 10 );
cout << "\n\nStats after resizing by (length + 10):\n";
printStatistics( string1 ); 45
cout << endl;
return 0; 48
49 } // end main 50
fig15_05.cpp (2 of 3)
Resize string.

23. fig15_05.cpp (3 of 3) fig15_05.cpp output (1 of 2)
51 // display string statistics
52 void printStatistics( const string &stringRef )
53 {
cout << "capacity: " << stringRef.capacity()
<< "\nmax size: " << stringRef.max_size()
<< "\nsize: " << stringRef.size()
<< "\nlength: " << stringRef.length()
<< "\nempty: " << stringRef.empty(); 59
60 } // end printStatistics
Display various string characteristics.
fig15_05.cpp (3 of 3) fig15_05.cpp output (1 of 2)
Statistics before input:
capacity: 0
max size:
size: 0
length: 0
empty: true
Enter a string: tomato soup
The string entered was: tomato
Statistics after input:
capacity: 31
size: 6
length: 6
empty: false

24. fig15_05.cpp output (2 of 2) The remaining string is: soup
capacity: 31
max size:
size: 4
length: 4
empty: false
string1 is now: soup abcdefghijklmnopqrstuvwxyz
capacity: 63
size: 50
length: 50
Stats after resizing by (length + 10):
size: 60
length: 60
fig15_05.cpp output (2 of 2)

25. 15.7 Finding Strings and Characters in a string
Find functions
If found, index returned
If not found, string::npos returned
Public static constant in class string
s1.find( s2 )
s1.rfind( s2 )
Searches right-to-left
s1.find_first_of( s2 )
Returns first occurrence of any character in s2
s1.find_frist_of( "abcd" )
Returns index of first 'a', 'b', 'c' or 'd'

26. 15.7 Finding Strings and Characters in a string
Find functions
s1.find_last_of( s2 )
Finds last occurrence of any character in s2
s1.find_first_not_of( s2 )
Finds first character NOT in s2
s1.find_last_not_of( s2 )
Finds last character NOT in s2

27. Note call to function find.
// Fig. 15.6: fig15_06.cpp
// Demonstrating the string find member functions
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string string1( "noon is 12 p.m." );
int location; 16
// find "is" at location 5
cout << "Original string:\n" << string1
<< "\n\n(find) \"is\" was found at: "
<< string1.find( "is" )
<< "\n(rfind) \"is\" was found at: "
<< string1.rfind( "is" ); 23
// find 'o' at location 1
location = string1.find_first_of( "misop" );
fig15_06.cpp (1 of 3)
Note call to function find.
Find first occurrence of m, i, s, o or p.

28. Calls to other find functions similar. fig15_06.cpp (2 of 3)26
cout << "\n\n(find_first_of) found '" << string1[ location ]
<< "' from the group \"misop\" at: "
<< location; 30
// find 'm' at location 13
location = string1.find_last_of( "misop" );
cout << "\n\n(find_last_of) found '" << string1[ location ]
<< "' from the group \"misop\" at: "
<< location; 36
// find '1' at location 8
location = string1.find_first_not_of( "noi spm" );
cout << "\n\n(find_first_not_of) '" << string1[ location ]
<< "' is not contained in \"noi spm\" and was found at:"
<< location; 42
// find '.' at location 12
location = string1.find_first_not_of( "12noi spm" );
cout << "\n\n(find_first_not_of) '" << string1[ location ]
<< "' is not contained in \"12noi spm\" and was "
<< "found at:" << location << endl;
Calls to other find functions similar.
fig15_06.cpp (2 of 3)

29. fig15_06.cpp (3 of 3) fig15_06.cpp output (1 of 1)48
// search for characters not in string1
location = string1.find_first_not_of( "noon is 12 p.m." );
cout << "\nfind_first_not_of(\"noon is 12 p.m.\")"
<< " returned: " << location << endl; 53
return 0; 55
56 } // end main
fig15_06.cpp (3 of 3) fig15_06.cpp output (1 of 1)
Original string:
noon is 12 p.m.
(find) "is" was found at: 5
(rfind) "is" was found at: 5
(find_first_of) found 'o' from the group "misop" at: 1
(find_last_of) found 'm' from the group "misop" at: 13
(find_first_not_of) '1' is not contained in "noi spm" and was found at:8
(find_first_not_of) '.' is not contained in "12noi spm" and was found at:12
find_first_not_of("noon is 12 p.m.") returned: -1

30. 15.8 Replacing Characters in a string
s1.erase( start )
Erase from index start to end of string, including start
Replace
s1.replace( begin, N, s2)
begin: index in s1 to start replacing
N: number of characters to replace
s2: replacement string
s1.replace( begin, N, s2, index, num )
index: element in s2 where replacement begins
num: number of elements to use when replacing
Replacement can overwrite characters
string::npos represents max string length

31. fig15_07.cpp (1 of 2) 1 // Fig. 15.7: fig15_07.cpp
// Demonstrating string member functions erase and replace.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
// compiler concatenates all parts into one string
string string1( "The values in any left subtree"
"\nare less than the value in the"
"\nparent node and the values in"
"\nany right subtree are greater"
"\nthan the value in the parent node" ); 20
cout << "Original string:\n" << string1 << endl << endl; 22
// remove all characters from (and including) location 62
// through the end of string1
string1.erase( 62 ); 26
fig15_07.cpp (1 of 2)

32. string::npos represents max string length.
// output new string
cout << "Original string after erase:\n" << string1
<< "\n\nAfter first replacement:\n"; 30
// replace all spaces with period
int position = string1.find( " " ); 33
while ( position != string::npos ) {
string1.replace( position, 1, "." );
position = string1.find( " ", position + 1 );
} // end while 38
cout << string1 << "\n\nAfter second replacement:\n"; 40
// replace all periods with two semicolons
// NOTE: this will overwrite characters
position = string1.find( "." ); 44
while ( position != string::npos ) {
string1.replace( position, 2, "xxxxx;;yyy", 5, 2 );
position = string1.find( ".", position + 1 );
} // end while 49
cout << string1 << endl;
return 0; 52
53 } // end main
string::npos represents max string length.
fig15_07.cpp (2 of 2)
Find each space and replace with a '.'
Start each search at the next position.
Replace all '.' with two semicolons (the two characters at index 5).

33. fig15_07.cpp output (1 of 1) Original string:
The values in any left subtree
are less than the value in the
parent node and the values in
any right subtree are greater
than the value in the parent node
Original string after erase:
After first replacement:
The.values.in.any.left.subtree
are.less.than.the.value.in.the
After second replacement:
The;;alues;;n;;ny;;eft;;ubtree
are;;ess;;han;;he;;alue;;n;;he
fig15_07.cpp output (1 of 1)

34. 15.9 Inserting Characters into a string
s1.insert( index, s2 )
Inserts s2 before position index
s1.insert( index, s2, index2, N );
Inserts substring of s2 before position index
Substring is N characters, starting at index2

35. Insert all of string2 before element 10.
// Fig. 15.8: fig15_08.cpp
// Demonstrating class string insert member functions.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string string1( "beginning end" );
string string2( "middle " );
string string3( " " );
string string4( "xx" ); 18
cout << "Initial strings:\nstring1: " << string1
<< "\nstring2: " << string2 << "\nstring3: " << string3
<< "\nstring4: " << string4 << "\n\n"; 22
// insert "middle" at location 10 in string1
string1.insert( 10, string2 ); 25
fig15_08.cpp (1 of 2)
Insert all of string2 before element 10.

36. fig15_08.cpp (2 of 2) fig15_08.cpp output (1 of 1)
// insert "xx" at location 3 in string3
string3.insert( 3, string4, 0, string::npos ); 28
cout << "Strings after insert:\nstring1: " << string1
<< "\nstring2: " << string2 << "\nstring3: " << string3
<< "\nstring4: " << string4 << endl; 32
return 0; 34
35 } // end main
Insert all of string4 before index 3.
fig15_08.cpp (2 of 2) fig15_08.cpp output (1 of 1)
Initial strings:
string1: beginning end
string2: middle
string3:
string4: xx
Strings after insert:
string1: beginning middle end
string3: 123xx45678

37. 15.10 Conversion to C-Style char * Strings
Conversion functions
strings not necessarily null-terminated
s1.copy( ptr, N, index )
Copies N characters into the array ptr
Starts at location index
Need to null terminate
s1.c_str()
Returns const char *
Null terminated
s1.data()
NOT null-terminated

38. Note calls to copy and c_str.
// Fig. 15.9: fig15_09.cpp
// Converting to C-style strings.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string string1( "STRINGS" );
const char *ptr1 = 0;
int length = string1.length();
char *ptr2 = new char[ length + 1 ]; // including null 18
// copy characters from string1 into allocated memory
string1.copy( ptr2, length, 0 );
ptr2[ length ] = '\0'; // add null terminator 22
// output
cout << "string s is " << string1
<< "\nstring1 converted to a C-Style string is "
<< string1.c_str() << "\nptr1 is ";
fig15_09.cpp (1 of 2)
Note calls to copy and c_str.

39. fig15_09.cpp (2 of 2) fig15_09.cpp output (1 of 1)27
// Assign to pointer ptr1 the const char * returned by
// function data(). NOTE: this is a potentially dangerous
// assignment. If string1 is modified, pointer ptr1 can
// become invalid.
ptr1 = string1.data(); 33
// output each character using pointer
for ( int i = 0; i < length; i++ )
cout << *( ptr1 + i ); // use pointer arithmetic 37
cout << "\nptr2 is " << ptr2 << endl;
delete [] ptr2;
return 0; 41
42 } // end main
fig15_09.cpp (2 of 2) fig15_09.cpp output (1 of 1)
string s is STRINGS
string1 converted to a C-Style string is STRINGS
ptr1 is STRINGS
ptr2 is STRINGS

40. 15.11 Iterators Iterators Forwards and backwards traversal of strings
Access to individual characters
Similar to pointer operations
More coverage in Chapter 20

41. 15.11 Iterators Basic usage Creation Referencing
string::const_iterator i = s.begin();
const, cannot modify string (more Chapter 20)
Referencing
*i; // reference character
++i; // traverse one character forward
Test for end of string
i != s.end()
end returns iterator after last element of s

42. Print each character using the iterator.
// Fig. 15.10: fig15_10.cpp
// Using an iterator to output a string.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 int main()
13 {
string string1( "Testing iterators" );
string::const_iterator iterator1 = string1.begin(); 16
cout << "string1 = " << string1
<< "\n(Using iterator iterator1) string1 is: "; 19
// iterate through string
while ( iterator1 != string1.end() ) {
cout << *iterator1; // dereference iterator to get char
iterator1; // advance iterator to next char
} // end while 25
cout << endl;
return 0; 28
29 } // end main
fig15_10.cpp (1 of 1)
Print each character using the iterator.

43. fig15_10.cpp output (1 of 1) string1 = Testing iterators
(Using iterator iterator1) string1 is: Testing iterators
fig15_10.cpp output (1 of 1)

44. 15.12 String Stream Processing
I/O of strings to and from memory
Called in-memory I/O or string stream processing
Classes
istringstream (input from string)
ostringstream (output to a string)
<sstream> and <iostream> headers
Use string formatting to save data to memory

45. 15.12 String Stream Processing
String output
Ostringstream outputString;
outputString << s1 << s2;
Member function str
Returns string that was output to memory
outputString.str()

46. Create ostringstream object.
// Fig. 15.11: fig15_11.cpp
// Using a dynamically allocated ostringstream object.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 #include <sstream> 13
14 using std::ostringstream; 15
16 int main()
17 {
ostringstream outputString; // create ostringstream instance 19
string string1( "Output of several data types " );
string string2( "to an ostringstream object:" );
string string3( "\n double: " );
string string4( "\n int: " );
string string5( "\naddress of int: " );
fig15_11.cpp (1 of 2)
Create ostringstream object.

47. Output format just like to writing to cout.25
double double1 = ;
int integer = 22; 28
// output strings, double and int to outputString
outputString << string1 << string2 << string3 << double1
<< string4 << integer << string5 << &integer; 32
// call str to output contents
cout << "outputString contains:\n" << outputString.str(); 35
// add additional characters and call str to output string
outputString << "\nmore characters added";
cout << "\n\nafter additional stream insertions,\n"
<< "outputString contains:\n" << outputString.str()
<< endl; 41
return 0; 43
44 } // end main
fig15_11.cpp (2 of 2)
Output format just like to writing to cout.

48. fig15_11.cpp output (1 of 1) outputString contains:
Output of several data types to an ostringstream object:
double:
int: 22
address of int: 0012FE94
after additional stream insertions,
more characters added
fig15_11.cpp output (1 of 1)

49. 15.12 String Stream Processing
String input
istringstream inputString ( myString );
inputString >> string1 >> string2
Like reading from cin

50. Create and initialize istringstream object.
// Fig. 15.12: fig15_12.cpp
// Demonstrating input from an istringstream object.
#include <iostream> 4
using std::cout;
using std::endl; 7
#include <string> 9
10 using std::string; 11
12 #include <sstream> 13
14 using std::istringstream; 15
16 int main()
17 {
string input( "Input test A" );
istringstream inputString( input );
string string1;
string string2;
int integer;
double double1;
char character; 25
fig15_12.cpp (1 of 2)
Create and initialize istringstream object.

51. Read data into variables. fig15_12.cpp (2 of 2)
inputString >> string1 >> string2 >> integer >> double1
>> character; 28
cout << "The following items were extracted\n"
<< "from the istringstream object:"
<< "\nstring: " << string1
<< "\nstring: " << string2
<< "\n int: " << integer
<< "\ndouble: " << double1
<< "\n char: " << character; 36
// attempt to read from empty stream
long value; 39
inputString >> value; 41
// test stream results
if ( inputString.good() )
cout << "\n\nlong value is: " << value << endl;
else
cout << "\n\ninputString is empty" << endl; 47
return 0; 49
50 } // end main
Read data into variables.
fig15_12.cpp (2 of 2)
good returns 1 if can still read data (no EOF, bad bits, etc). In this case, there is no data, so the test fails.

52. fig15_12.cpp output (1 of 1) The following items were extracted
from the istringstream object:
string: Input
string: test
int: 123
double: 4.7
char: A
inputString is empty
fig15_12.cpp output (1 of 1)