# std::istrstream::istrstream

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< cpp‎ | io‎ | istrstream

explicit istrstream( const char* s ); | (1) | (deprecated in C++98) (removed in C++26)
explicit istrstream( char* s ); | (2) | (deprecated in C++98) (removed in C++26)
istrstream( const char* s, std::streamsize n ); | (3) | (deprecated in C++98) (removed in C++26)
istrstream( char* s, std::streamsize n ); | (4) | (deprecated in C++98) (removed in C++26)

Constructs new std::istrstream and its underlying std::strstreambuf.

1,2) Constructs the underlying std::strstreambuf by calling strstreambuf(s, 0) and initializes the base class with the address of the `strstreambuf`. The behavior is undefined if s is not pointing at an element of a null-terminated array.
3,4) Constructs the underlying std::strstreambuf by calling strstreambuf(s, n) and initializes the base class with the address of the `strstreambuf`. The behavior is undefined if s is not pointing at an element of an array whose length is at least n elements.

### Parameters

s | - | C-string or char array to use as the contents of the stream
n | - | size of the array

### Example

Run this code

    #include <iostream>
    #include <strstream>

    int main()
    {
        std::istrstream s1("1 2 3"); // string literal
        int n1, n2, n3;
        if (s1 >> n1 >> n2 >> n3)
            std::cout << n1 << ", " << n2 << ", " << n3 << '\n';

        char arr[] = {'4', ' ', '5', ' ', '6'};
        std::istrstream s2(arr, sizeof arr);
        if (s2 >> n1 >> n2 >> n3)
            std::cout << n1 << ", " << n2 << ", " << n3 << '\n';
    }

Output:

    1, 2, 3
    4, 5, 6

### See also

(constructor) | constructs a `strstreambuf` object (public member function of `std::strstreambuf`)
(constructor) | constructs an `ostrstream` object, optionally allocating the buffer (public member function of `std::ostrstream`)
(constructor) | constructs a `strstream` object, optionally allocating the buffer (public member function of `std::strstream`)

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