Common Logic Errors
Incorrect mathematical formulae
Instructions written (and therefor executed) in the wrong order.
Incorrect conditions provided for loops/selection statements.
Will usually run normally but with some unexpected results.
Usually run normally while testing.
The code doesn't do what id should.
May sometimes cause a run-time error.
The syntax of the code is correct.
Common Run-time Errors
Attempts to reference array elements before they are initialised.
Calculating routes of a negative number.
Attempts to access non-existent file.
Overflow error - result of calculation is a number that is too large.
Division by zero.
Program attempts impossible operation.
Usually detected while testing
Causes program to crash at run-time.
Common Syntax Errors
Using variables without declaring them.
Incorrect spelling of variables names.
Passing incorrect/insufficient parameters.
Missing parts of multiline statements.
Data type mismatch.
Usually detected during development.
Program will not be compiled.
Code does not follow the rules of the programming language.