Presence Check

A presence check is to check that data has actually been entered, this could cause errors in your program if you don't complete this check.

Length Check

This checks to see the data is the correct length. This shouldn't be confused with range as it counts the numbers of digits in the value. This could be important for passwords that need to be a specific length or an unique identifier.

Range Check

This is to check that the integer or float value falls between a specific range of values. Inserting a negative age may produce errors in your program

Look-up Table

A very simple form of checking where you check that an inserted value matches a preset list. This stops users entering a made up address or spelling their address incorrectly.

Format Check

This checks that data is in a specific format to be processed later. For example a date should only be accepted if the date is valid and a date can be understood from what the user input. For a postcode it must be 2 letters, 1 number then 1 number and 2 letters.

Type Check

This checks that the data input is the correct data type. Storing an age as a float could cause you errors later on or even entering a string could cause even worse errors.

Correct Check

When performing tests it is important to make sure that you test that the program actually works correctly.