重构我臃肿的代码的好方法是什么？

Question

我做了一个简单的 D&D 掷骰子应用程序用于练习，并注意到有很多重复的代码。 不过，我找不到自己重构它的好方法。 任何提示表示赞赏。 公平警告，我是一个菜鸟，所以我已经知道它可能有比我意识到的更多的问题。 随意让我拥有它。

https://jsfiddle.net/sakonexus/nd82qjec/

function calcRoll(e) {
  let die = e.target.previousElementSibling.name;
  let rolls = e.target.previousElementSibling.value;
  let topRow = {};
  let bottomRow = {};
  let randomRoll = 0;
  
  if (rolls == '') {
    rolls = 0;
  }
  
  if (die.includes("d4")) {
    topRow = document.getElementById("d4-roll-results").insertRow(0);
    bottomRow = document.getElementById("d4-roll-results").insertRow(1);
    topRow.insertCell(0).innerHTML = "Roll Count";
    bottomRow.insertCell(0).innerHTML = "Roll Result";
    
    for(i = 0; i < rolls; i++) {
      topRow.insertCell(i + 1).innerHTML = i + 1;
    }
    
    for(j = 0; j < rolls; j++) {
        randomRoll = Math.floor(Math.random() * 4) + 1;
        bottomRow.insertCell(j + 1).innerHTML = randomRoll;
    }
  } else if (die.includes("d6")) {
    topRow = document.getElementById("d6-roll-results").insertRow(0);
    bottomRow = document.getElementById("d6-roll-results").insertRow(1);
    topRow.insertCell(0).innerHTML = "Roll Count";
    bottomRow.insertCell(0).innerHTML = "Roll Result";
    
    for(i = 0; i < rolls; i++) {
      topRow.insertCell(i + 1).innerHTML = i + 1;
    }
    
    for(j = 0; j < rolls; j++) {
        randomRoll = Math.floor(Math.random() * 6) + 1;
        bottomRow.insertCell(j + 1).innerHTML = randomRoll;
    }
  } else if (die.includes("d8")) {
    topRow = document.getElementById("d8-roll-results").insertRow(0);
    bottomRow = document.getElementById("d8-roll-results").insertRow(1);
    topRow.insertCell(0).innerHTML = "Roll Count";
    bottomRow.insertCell(0).innerHTML = "Roll Result";
    
    for(i = 0; i < rolls; i++) {
      topRow.insertCell(i + 1).innerHTML = i + 1;
    }
    
    for(j = 0; j < rolls; j++) {
        randomRoll = Math.floor(Math.random() * 8) + 1;
        bottomRow.insertCell(j + 1).innerHTML = randomRoll;
    }
  } else if (die.includes("d10")) {
    topRow = document.getElementById("d10-roll-results").insertRow(0);
    bottomRow = document.getElementById("d10-roll-results").insertRow(1);
    topRow.insertCell(0).innerHTML = "Roll Count";
    bottomRow.insertCell(0).innerHTML = "Roll Result";
    
    for(i = 0; i < rolls; i++) {
      topRow.insertCell(i + 1).innerHTML = i + 1;
    }
    
    for(j = 0; j < rolls; j++) {
        randomRoll = Math.floor(Math.random() * 10);
        bottomRow.insertCell(j + 1).innerHTML = randomRoll;
    }
  } else if (die.includes("d12")) {
    topRow = document.getElementById("d12-roll-results").insertRow(0);
    bottomRow = document.getElementById("d12-roll-results").insertRow(1);
    topRow.insertCell(0).innerHTML = "Roll Count";
    bottomRow.insertCell(0).innerHTML = "Roll Result";
    
    for(i = 0; i < rolls; i++) {
      topRow.insertCell(i + 1).innerHTML = i + 1;
    }
    
    for(j = 0; j < rolls; j++) {
        randomRoll = Math.floor(Math.random() * 12) + 1;
        bottomRow.insertCell(j + 1).innerHTML = randomRoll;
    }
  } else if (die.includes("d20")) {
    topRow = document.getElementById("d20-roll-results").insertRow(0);
    bottomRow = document.getElementById("d20-roll-results").insertRow(1);
    topRow.insertCell(0).innerHTML = "Roll Count";
    bottomRow.insertCell(0).innerHTML = "Roll Result";
    
    for(i = 0; i < rolls; i++) {
      topRow.insertCell(i + 1).innerHTML = i + 1;
    }
    
    for(j = 0; j < rolls; j++) {
        randomRoll = Math.floor(Math.random() * 20) + 1;
        bottomRow.insertCell(j + 1).innerHTML = randomRoll;
    }
  }
  
  
}

Answer 1

首先，您应该避免使用内联处理程序，它们有太多值得使用的问题。 使用 JavaScript 和addEventListener正确附加侦听器。

单击按钮时，导航到其父窗体或 div 以识别骰子的类型。 然后，从父 div 导航到 div 的表子项并填充它：

 document.querySelector('#dice').addEventListener('click', (e) => { if (!e.target.matches('button')) { return; } e.preventDefault(); const { target } = e; const div = target.closest('div'); const dieType = div.dataset.dieType; const numDice = target.previousElementSibling.value; const table = div.querySelector('table'); table.innerHTML += ` <tr> <td>Roll Count</td> ${Array.from({ length: numDice }, (_, i) => `<td>${i + 1}</td>`).join('')} </tr> <tr> <td>Roll Result</td> ${Array.from({ length: numDice }, () => `<td>${Math.floor(Math.random() * dieType) + 1}</td>`).join('')} </tr> `; });

 #dice table { border-collapse: collapse; } #dice td { border: 1px solid black; padding: 4px; } #dice div { padding: 10px 0 0; }

 <div> <h1>Select the number of rolls for each dice</h1> <div id="dice"> <div data-die-type="4"> <form> <label><span>D4&#160;&#160;</span><input type="number" min="0" max="10"><button>Confirm</button></label> </form> <div><table></table></div> </div> <hr /> <div data-die-type="6"> <form> <label><span>D6&#160;&#160;</span><input type="number" min="0" max="10"><button>Confirm</button></label> </form> <div><table></table></div> </div> <hr /> <div data-die-type="8"> <form> <label><span>D8&#160;&#160;</span><input type="number" min="0" max="10"><button>Confirm</button></label> </form> <div><table></table></div> </div> <hr /> <div data-die-type="10"> <form> <label><span>D10</span><input type="number" min="0" max="10"><button>Confirm</button></label> </form> <div><table></table></div> </div> <hr /> <div data-die-type="12"> <form> <label><span>D12</span><input type="number" min="0" max="10"><button>Confirm</button></label> </form> <div><table></table></div> </div> <hr /> <div data-die-type="20"> <form> <label><span>D20</span><input type="number" min="0" max="10"><button>Confirm</button></label> </form> <div><table></table></div> </div> </div> </div>

看看如何让您的 HTML 变得更加 DRY - 不需要所有这些不同的 ID 和属性。