As described above, an integer variable has no fractional part. Integer variables tend to be used for counting, whereas real numbers are used in arithmetic. C uses one of two keywords to declare a variable that is to be associated with a decimal number: float and double. They are each offer a different level of precision as outlined below.
float
A float, or floating point, number has about seven digits of precision and a range of about 1.E-36 to 1.E+36. A float takes four bytes to store.
double
A double, or double precision, number has about 13 digits of precision and a range of about 1.E-303 to 1.E+303. A double takes eight bytes to store.
For example:
float total;
double sum;
To assign a numerical value to our floating point and double precision variables we would use the following C statement:
total=0.0;
sum=12.50;
float
A float, or floating point, number has about seven digits of precision and a range of about 1.E-36 to 1.E+36. A float takes four bytes to store.
double
A double, or double precision, number has about 13 digits of precision and a range of about 1.E-303 to 1.E+303. A double takes eight bytes to store.
For example:
float total;
double sum;
To assign a numerical value to our floating point and double precision variables we would use the following C statement:
total=0.0;
sum=12.50;