How strictly types are enforced.
WHAT STRONG TYPING MEANS
Types are enforced, and conversions must be explicit.
WHAT WEAK TYPING MEANS
Values are converted automatically between types.
WHY THAT MATTERS
Automatic conversion produces surprising results.
WHAT THAT LOOKS LIKE
Text and a number compared, or added, producing something unintended.
WHAT THAT CAUSES
Bugs that are difficult to trace, because nothing appears wrong.
WHAT TO DO IN WEAKLY TYPED LANGUAGES
Use strict comparison, which checks type as well as value Convert explicitly Validate input types
WHAT IS INDEPENDENT OF STATIC AND DYNAMIC
Strength. A language can be dynamically and strongly typed.
WHAT THAT MEANS
Adding text to a number fails, rather than producing something.
WHY THAT IS PREFERABLE
Failing is better than silently continuing with a wrong value.
WHAT TO ESTABLISH IN ANY LANGUAGE
Where implicit conversion happens.
WHY
That is where the surprises are.
