The basic forms of data that can be entered into a cell include strings, numbers, formulas, and cell references.
The simplest of these types are strings and numbers. They are just constant values that are stored in a cell. There is no special syntax for this kind of data. The only limitation is that strings and numbers cannot contain newlines or begin with a '='. The '=' is used to denote cells that contain formulas or cell references.
See Figure 1-1 for an example of entering a string.
Dates and numbers are a special case of strings that are automatically converted to numerical types. If a string entered matches one of the formats for dates or times, the string is converted into a serial number (representative of the time in the string) and the cell format is set to that of the original string.
To make use of this feature, the user just needs to enter in a number in a recognizable format. Gnumeric will automatically convert it into an appropriate serial number. Because of this, it is possible to enter a date or time in a human readable format, and have it stored in a numerical format inside of Gnumeric.
The interesting part of this is that a user entered string, can be autofilled (see the section called Autofill) properly.
See Example 3-3 for some examples of the many date and time formats that are accepted by Gnumeric.
Entering data in a cell
Activate the cell by clicking on it with the white-cross cursor. This will make the cell become the active cell (see Figure 1-4).
Type in the data or formula.
See the section called Formulas for more detail on entering formulas into cells.
After selecting the cell and initially e