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ldexp() - Mantissa and Exponent - C++ Mathematical Function Tutorial
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# ldexp() - Mathematical Function

How is Mathematical Function "ldexp()" used in C++?
How to generate number from mantissa and exponent?

## Explanation

ldexp() is a Mathematical Function that returns the resulting floating point value from multiplying the mantissa (x) by 2 raised to the power of exponent(exp).(i.e) It returns the value of "num * 2exp ". If an overflow occurs "HUGE_VAL" is returned.

### Syntax:

float ldexp( float num, int exp);
double ldexp( double num, int exp);
long double ldexp( long double num, int exp);

#### Example :

 #include #include int main(){double num, r;int exp=4;num = 8.0;r = ldexp( num, exp);printf( "%lf times of 2 to the powerof %d is:: %lf\n", num,exp, r);return 0;}

Result :

8.000000 times of 2 to the power of 4 is:: 128.000000

In the above example ldexp() returns the value of "8*24".Thus a floating point number is generated from the mantissa(8.0) and exponent(4).