hints.md

Hints

General

• The introduction covers the comparison operators you need for this exercise.
• You may also review the comparison operators documentation.

1. Calculate the success rate

• Compare $speed with the boundary values from the table (===, >=, >, <=, or < as needed).
• You can use a simple if statement to return the matching success rate.

2. Calculate the production rate per hour

• Reuse the successRate() method you wrote earlier: $this->successRate($speed).
• Multiply 221, $speed, and the success rate.
• PHP can multiply integers and floating-point numbers together; the result may be a float.

3. Check whether the line is running

• Use a not-identical comparison (!==) against 0.
• Return the boolean result of that comparison.

4. Compare two line speeds

• The spaceship operator (<=>) returns -1, 0, or 1 directly.