Scientific Notation

Scientific notation is another way to write a number. In scientific notation, the letter E is used to mean "10 to the power of." For example, 1.314E+1  means  1.314 * 101  which is 13.14.

Scientific notation is merely a format used for character input and output. The 64-bit pattern used for a double inside the computer is the same, no matter what character format was used for input. Here is an example:

C:\temp>java DoubleDouble
Enter a double: 1.234E+9
value: 1.234E9 twice value: 2.468E9

Here the user entered data using scientific notation, and nextDouble() converted those characters into a double. If the user entered 1234000000, those characters would be converted into the same double.

When a double is converted into characters, scientific notation is used when needed for very large or very small values.

The input characters may use an upper or lower case "e":

C:\temp>java DoubleDouble
Enter a double: -7.001e-2
value: -0.07001 twice value: -0.14002

In this example, the user chose scientific notation for input. On output, the values were in the normal range and the ordinary number format was used.