str

Syntax:

    #include 
void str( string s );
string str();

The function str() can be used in two ways. First, it can be used to get a copy of the string that is being manipulated by the current stream string. This is most useful with output strings. For example:

    ostringstream stream1;
stream1 << "Testing!" << endl;
cout << stream1.str();

Second, str() can be used to copy a string into the stream. This is most useful with input strings. For example:

    istringstream stream1;
string string1 = "25";
stream1.str(string1);

str(), along with clear(), is also handy when you need to clear the stream so that it can be reused:

    istringstream stream1;
float num;
 
// use it once
string string1 = "25 1 3.235\n1111111\n222222";
stream1.str(string1);
while( stream1 >> num ) cout << "num: " << num << endl; // displays numbers, one per line
 
// use the same string stream again with clear() and str()
string string2 = "1 2 3 4 5 6 7 8 9 10";
stream1.clear();
stream1.str(string2);
 
while( stream1 >> num ) cout << "num: " << num << endl; // displays numbers, one per line

Related Topics: rdbuf, C++ I/O Streams

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