Scientific Notation

Scientific notation is another way of using characters to express a number. When it is converted to a double you get the same double that you would get with ordinary notation. 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 input and output. The 64-bit pattern used for a double inside the computer are 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

In this example, the user entered character data using scientific notation, and those characters were converted into a double. If the user had entered 1234000000, those characters would be converted into the same double. On output, scientific notation is used because the value is big, not because the input used scientific notation. The "E" may be upper or lower case:

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

In this example, scientific notation was used with the characters that were read in. Those characters were converted to a double value. Some arithmetic was done with that value and the results were converted to characters and written out. Since the values were in the normal range of numbers, ordinary formats were used for the output characters.