ios - What is the difference between $(PROJECT_DIR) and $(SRCROOT) in actual development of Xcode.

Question

During development, I saw two different ways of writing $(PROJECT_DIR) and $(SRCROOT) in the application. What is the difference between the two?

Answer 1

The animationDemo on the left is PROJECT_DIRanimationDemo是PROJECT_DIR
右边的animationDemo是SRCROOTThe animationDemo on the right is SRCROOT