Syntax error

• Missing extra brackets
• Using variables
• Brackets not used properly
• The statement in the code does not follow the rules of the language.
• Usually detected by the translator, as the statement cannot be understood.
• Programs will not be compiled

Logic Error

• The syntax of the code is correct
• the code does not do what it should
• Will usually run normally but with some unexpected result
• Usually tested while being tested
• Incorrect mathematical formulae
• Misplaced brackets
• Instruction written and therefore executed in the wrong order

Run time error

• The syntax is correct
• the logic of the program is correct
• extreme circumstances cause crash
• program attempts impossible operation
• causes program to crash at run time
• usually detected while testing
• Division by zero
• attempt to access non existent file
• attempt to reference array elements before they are initialised 

Test Data

Data which syhold genarate an error message