能否在Processing 3中实现Stack？IDE提示"the function push(String) does not exist"

Hey there! Absolutely, you can implement a Stack data structure in Processing 3—let’s break down why you’re seeing that error and how to fix it, plus walk through two solid implementation options.

Why the Error Happens #

The "the function push(String) does not exist" message pops up because Processing has a built-in global push() function that’s used for saving drawing state (like transformations, color styles, or font settings). This built-in function takes no arguments, so when you try to call it with a String parameter, the IDE can’t find a matching function and throws an error.

Chances are, you were trying to call a push method for your custom Stack—but you either forgot to tie it to a Stack object, or your method name clashed with Processing’s built-in push().

Solution 1: Build a Custom Stack Class (Recommended) #

Create your own Stack class with unique method names to avoid conflicts with Processing’s built-in functions. Here’s a complete example for a String-focused stack:

class StringStack {
  private ArrayList<String> stackItems;

  // Constructor to initialize the stack
  StringStack() {
    stackItems = new ArrayList<String>();
  }

  // Use a unique name like pushItem instead of push
  void pushItem(String item) {
    stackItems.add(item);
  }

  // Remove and return the top item
  String popItem() {
    if (!isEmpty()) {
      return stackItems.remove(stackItems.size() - 1);
    }
    // Handle empty stack case (adjust based on your needs)
    println("Stack is empty!");
    return null;
  }

  // Check if stack is empty
  boolean isEmpty() {
    return stackItems.isEmpty();
  }

  // Peek at the top item without removing it
  String peekItem() {
    if (!isEmpty()) {
      return stackItems.get(stackItems.size() - 1);
    }
    println("Stack is empty!");
    return null;
  }
}

// Use the stack in your sketch
StringStack myStack;

void setup() {
  size(400, 200);
  myStack = new StringStack();
  
  // Add items to the stack
  myStack.pushItem("Hello");
  myStack.pushItem("Processing");
  myStack.pushItem("Stacks!");
  
  // Test popping items
  println(myStack.popItem()); // Output: Stacks!
  println(myStack.peekItem()); // Output: Processing
}

Solution 2: Use Java’s Built-in Stack Class #

Since Processing is built on Java, you can directly use the java.util.Stack class. This avoids writing your own stack from scratch, and since you’ll call push on a Stack object (not as a global function), it won’t clash with Processing’s built-in push():

// Import the Java Stack class
import java.util.Stack;

Stack<String> myStack;

void setup() {
  size(400, 200);
  myStack = new Stack<String>();
  
  // Add items using the Stack object's push method
  myStack.push("First entry");
  myStack.push("Second entry");
  
  // Test stack operations
  println(myStack.pop()); // Output: Second entry
  println(myStack.isEmpty()); // Output: false
}

Quick Troubleshooting Tip #

If you still run into issues, double-check that you’re calling the push method on your Stack object (e.g., myStack.pushItem(...) or myStack.push(...)) instead of calling the global push() function directly with a parameter.

内容的提问来源于stack exchange，提问作者Askhento