CS 70

Context Matters

This is a quick whole class activity, not a group one. ['Prof. Melissa'] will be at the board to talk through this one.

Random Character in a File, Part 1 a “-” sign.

Suppose someone says to you, “I'm looking at a C++ source file and I see a - character. Can you tell me what it might signify?”

Is that enough context to give a definitive answer?

As a group, ponder the question: In code, what does the “-” sign mean?

  • If the answer is, “it depends”, depends on what?

Random Character in a File, Part 2 a “&” sign.

Similarly, suppose someone says to you, “I'm looking at a C++ source file and I see a & character. Can you tell me what it might signify?”

Terminology

Notice some different C++ contexts:

Code Context
int x = 42; declaration (and definition)
setupFarm(3); statement
a + b expression
x = a; assignment

Context Matters

Explain why each of these bits of code is nonsensical:

  • "mint" x = 42;
  • setupFarm(int);
  • a +

(When logged in, completion status appears here.)