Data+validation

= Data Validation =


 * Data validation** is the process of ensuring that a program operates on clean, correct and useful data. It uses routines, often called " validation rules " or "check routines", that check for correctness, meaningfulness, and security of data that are input to the system.

Examples:


 * Data type checks- Checks the data type of the input and give an error message if the input data does not match with the chosen data type, e.g., In an input box accepting numeric data, if the letter 'O' was typed instead of the number zero, an error message would appear.
 * Logic check- Checks that an input does not yield a logical error
 * Presence check- Checks that important data are actually present and have not been missed out, e.g., customers may be required to have their telephone numbers listed.
 * Range check- Checks that the data lie within a specified range of values, e.g., the month of a person's date of birth should lie between 1 and 12.
 * Spelling and grammar check- Looks for spelling and grammatical errors.