新手求助：计算器总值检测与化学式匹配功能开发方向指引

Hey there! Since you're a programming newbie, let's break this down into simple, actionable steps that fit right into your existing calculator code. I'll even include code snippets based on the fragment you shared to make it easier to follow.

核心思路拆解 #

• 第一步：建立按键与数值的映射
  You mentioned the O key equals 9 and C equals 8—first, we need a way to tell the calculator which key corresponds to which number. We can use a simple JavaScript object for this, like a lookup table.

• 第二步：跟踪输入的计算内容
  Your existing inputs array is probably storing the sequence of keys pressed (like numbers and operators). We'll use this array to build the full calculation string before computing the total.

• 第三步：捕获计算完成的时机
  When the user presses the equals (=) key (or whatever triggers the calculation), we'll compute the total value from the input sequence.

• 第四步：检测目标总值并触发提示
  After getting the total, check if it matches your target (like 17). If it does, show the custom message you want.

代码示例（基于你的初始片段） #

Here's how you can modify your existing code to add this feature:

$(document).ready(function(){
  var inputs = [""];
  var totalString;
  
  // Step 1: Define your key-to-number mapping here
  const keyToValue = {
    'O': '9',
    'C': '8',
    // Add other key mappings here if you have more, e.g., 'X': '7'
    '+': '+', // Don't forget operators like addition!
    '-': '-',
    '*': '*',
    '/': '/'
  };

  // Assume your calculator keys have a class like "calc-key" (adjust to your actual selector)
  $('.calc-key').click(function() {
    const pressedKey = $(this).text();

    // Handle number/operator keys
    if (keyToValue[pressedKey]) {
      // Add the mapped value to our input sequence
      inputs.push(keyToValue[pressedKey]);
      // Update the calculator display (replace #display with your actual display element ID)
      $('#display').text(inputs.join(''));
    } 
    // Handle equals key to compute total
    else if (pressedKey === '=') {
      try {
        // Combine the input sequence into a single calculation string
        totalString = inputs.join('');
        // Compute the total (eval is simple for beginners—note: avoid in production code for security)
        const total = eval(totalString);

        // Step 4: Check if total matches your target value
        if (total === 17) {
          alert("You've created CO2");
          // Alternatively, show a message on the page instead of alert:
          // $('#custom-alert').text("You've created CO2").fadeIn();
        }

        // Update display with the result
        $('#display').text(total);
        // Reset input array with the result for next calculation
        inputs = [total.toString()];
      } catch (error) {
        // Handle invalid calculations (like 9++8)
        $('#display').text('Error');
        inputs = [""];
      }
    }
    // Handle clear key (adjust to your actual clear key text)
    else if (pressedKey === 'AC') {
      inputs = [""];
      $('#display').text('0');
    }
  });
});

新手友好的注意事项 #

• About eval(): Using eval() is super easy for beginners to compute the total, but it's not safe for production apps (since it can run malicious code). For practice though, it's perfect—later you can learn about safer calculation parsers if needed.
• Selector Adjustments: Make sure the selector for your keys (.calc-key) and display (#display) matches the IDs/classes in your HTML.
• Extending the Feature: If you want to add more target values later (like 20 = "You created H2O"), just make an object of targets and messages:

  const targetMessages = {
    17: "You've created CO2",
    20: "You've created H2O",
    9: "You've created O"
  };
  

  Then replace the alert check with:

  if (targetMessages[total]) {
    alert(targetMessages[total]);
  }
  

内容的提问来源于stack exchange，提问作者DodecaHEdron