What are different characteristics of design patterns?

A design pattern is a general repeatable solution to a commonly occurring problem in software design.
- It is a proven solution to problems that keep recurring.
- They are reusable solutions to common problems.
- Design patterns are not frameworks.
- Design patterns are more abstract than frameworks.
- Design pattern cannot be directly implemented.
- Design patterns are more primitive than a framework.
- A design pattern cannot incorporate a framework.
- Patterns may be documented using one of several alternative templates.
- Design patterns can speed up the development process by providing tested, proven development paradigms.
- Reusing design patterns helps to prevent subtle issues that can cause major problems and improves code readability for coders and architects familiar with the patterns.
- Patterns allow developers to communicate using well-known, well understood names for software interactions.

A pattern description includes the following elements:
- name of the pattern should be meaningful.
- context of the pattern represents the circumstances or preconditions.
- Problem description that pattern addresses should be provided.
- Solution is a description of the static and dynamic relationships amongthe components of the pattern.
The use of design patterns requires careful analysis of the problem that is to be
addressed and the context in which it occurs.

Static and Dynamic Analysis in Testing and their differences.

Static analysis involves going through the code in order to find out any possible defect in the code. Dynamic analysis involves executing the code and analyzing the output.

- Static testing is about prevention.
- In static testing, the software is not actually used.
- It is generally not detailed testing, but checks mainly for the sanity of the code, algorithm, or document. It is primarily syntax checking of the code or and manually reading of the code.
- This testing is used by the developer who writes the code in isolation.
- Out of Verification and Validation, it is the verification portion.
- Static testing methodologies include code reviews, inspection and walkthroughs.
- Dynamic testing is about cure.
- The source code is actually compiled and run.
- It examines the physical response from the system.
- Out of Verification and Validation, it is the validation portion.
- Dynamic testing methodologies include unit testing, integration testing, system testing and acceptance testing.
- Static testing is many times more cost-effective than dynamic testing.
- Static testing achieves 100 statement coverage in a relatively short time while dynamic testing often often achieves less than 50 statement coverage.
- Static testing can be done before compilation while dynamic testing can take place only after compilation and linking.
- Static check is more profitable than the dynamics of the static check because tests are made at the initial stage.

Why is static testing more effective?
Static testing gives you comprehensive diagnostics for your code. It warns you about:
- syntax errors.
- code that will be hard to maintain.
- code that will be hard to test.
- code that does not conform to your coding standards.
- non-portable usage.
- ANSI violations.