What is exp2() in D?

The exp2() function in D returns 22 raised to the power of a specific number.

The mathematical representation of the exp2() function is shown below.

Mathematical representation of the exp2() function

Note: We need to import std.math in our code in order to use the exp2() function. We can import it like this:
import std.math

Syntax

// The number should be floating, double, or real.
exp2(number)

Parameters

This function requires a number as a parameter.

Return value

The exp2() function returns 22 raised to the power of the specific number sent as a parameter.

Note:

  • If the parameter value is positive infinity, then exp2() returns positive infinity.
  • If the parameter value is negative infinity, exp2() returns 0.
  • If the parameter value is NaN, exp2() returns NaN.
  • If the parameter value is -NaN, exp2() returns -NaN.

Code

The code below shows how to use the exp2() function in D.

import core.stdc.stdio;
import std.stdio;
//Header required for the function
import std.math;
int main()
{
    //Integer
    writeln ("The value of exp2(10.0) : ",exp2(10.0));
    //Positive double value
    writeln ("The value of exp2(2.56) : ",exp2(2.56));
    //Negative double value
    writeln ("The value of exp2(-2.56) : ",exp2(-2.56));
    //Zero
    writeln ("The value of exp2(0.0) : ",exp2(0.0));
    //Exceptional outputs
    writeln ("The value of exp2(real.infinity) : ",exp2(real.infinity));
    writeln ("The value of exp2(-real.infinity) : ",exp2(-real.infinity));
    writeln ("The value of exp2(real.nan) : ",exp2(real.nan));
    writeln ("The value of exp2(-real.nan) : ",exp2(-real.nan));
    return 0;
}

Explanation

  • Line 4: We add the std.math header required for the exp2() function.

  • Line 9: We calculate the exponent with base 2 of the integer value using exp2().

  • Line 12: We calculate the exponent with base 2 of the positive double value using exp2().

  • Line 15: We calculate the exponent with base 2 of the negative double value using exp2().

  • Line 18: We calculate the exponent with base 2 of the zero using exp2().

  • Line 20 onwards: We calculate the exponent with base 2 of exceptional numbers using exp2().

Free Resources

License: Creative Commons-Attribution-ShareAlike 4.0 (CC-BY-SA 4.0)