A double is a data type. It is a floating-point number that has 64 bits of space.
Doubles are commonly used for large numbers in programming. Being floating-point numbers, doubles can hold decimal precision.
Doubles can be used for arithmetic expressions such as addition, multiplication, division in programming. It is functionally similar to a float data type, however, it can hold twice as much data. This means that the numbers used in a double can be twice as large or twice as accurate as that of a float.
double a = 5; double b = 2.5; double result1, result2, result3; // You can also declare several variables of the same type this way. result1 = a + b; // result1 = 7.5 result2 = a * b; // result2 = 12.5 result3 = a / b; // result3 = 2;