Expression examples Examples of common expressions used by report designers. Check a field for a valueCheck whether a field contains a value, is empty, or is null and act accordingly.Change the display based on a conditionChange the way your report displays depending on a condition in the RTL expression.Display an image based on a variableCheck the value of a variable and display the image specified by the variable.Size a column based on dataBase the size of a column on the size of the translated text displayed in it.Format a number within a stringInclude a formatted number in a text string.Related conceptsUsing a page number stringCustom keys