how to make negative numbers into positive

Question

I am having the negative floating point number as:

a = -0.340515;

to convert this into positive number I used the abs() method as:

Answer 1

Use float fabsf (float n) for float values.

Use double fabs (double n) for double values.

Use long double fabsl(long double) for long double values.

Use abs(int) for int values.