Which one of the following is not a source code metric ?

Answer: Function point metric is not a source code metric.

Why: Function points measure the software's functional size from the user's perspective (inputs, outputs, user interactions, files) and are independent of implementation or programming language. They are used for early estimation and planning rather than being calculated from source code.

Brief notes on the other metrics:

• Halstead metric: A source code metric based on counts of operators and operands; yields measures like program length, volume, difficulty, and effort.

• Complexity metric: A source code metric (for example, cyclomatic complexity) that measures control-flow or structural complexity directly from the code.

• Length metric: A source code metric that measures code size (for example, lines of code or Halstead program length).