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scalbln() function in C++ STL
• Last Updated : 12 Jul, 2018

The scalbln() is a built-in function in C++ STL which takes two arguments and scales x by FLT_RADIX raised to the power n. The function returns the product of x and FLT_RADIX raised to the power n.

FLT_RADIX: It is the value of the radix (integer base) of the exponent representation.

Syntax:

`scalbln (x, n)`

Parameters: The function accepts two mandatory parameters which are described below:

• x– It specifies the value representing the significand. The data-type can be double, float or long-double.
• n– It specifies the exponent of FLT_RADIX. The parameter is of data-type long-int.

Return Type: The function returns the product of x and FLT_RADIX raised to the power n. The returned value is of the same data-type as of x.

Below programs illustrate the above function:

Program 1:

 `// C++ program to illustrate``// scalbln() function``#include ``using` `namespace` `std;`` ` `int` `main()``{``    ``long` `int` `n = 0;``    ``double` `x = 2.12, result;``    ``result = scalbln(x, n);``    ``cout << x << ``" * "` `<< FLT_RADIX << ``"^"` `    ``<< n << ``" = "` `<< result << endl;`` ` `    ``return` `0;``}`
Output:
```2.12 * 2^0 = 2.12
```

Program 2:

 `// C++ program to illustrate``// scalbln() function``#include ``using` `namespace` `std;`` ` `int` `main()``{``    ``long` `int` `n = 9999999;``    ``double` `x = 19.8, result;``    ``result = scalbln(x, n);``    ``cout << x << ``" * "` `<< FLT_RADIX << ``"^"` `    ``<< n << ``" = "` `<< result << endl;`` ` `    ``return` `0;``}`
Output:
```19.8 * 2^9999999 = inf
```
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