javascript - 在JavaScript中重复功能不起作用

所以我试图做一个简单的翻译器。我只是有一些问题。例如，我希望它注册字母B，然后它会写bob。现在，当我在“转换为”框（这是普通变量）中写b时，它在“转换为”框（即theifTalk）[object HTMLTextAreaElement] bob中说。并在控制台中说：无法读取未定义的属性“重复”。无论如何，这是我的代码：

const theifTalk = document.getElementById('theiftalk');
const normal = document.getElementById('normal');
const translateBtn = document.getElementById('translateBtn');


translateBtn.onclick = function() {
    theifTalk.value = "";
    translate();
}

function translate() {

    if (normal.value.includes("b")) {
        var bCount = normal.value.match(/b/g)||[].length;

        b().repeat(bCount.length);
    }

}

function b() {
    theifTalk.value = theifTalk + "bob";
}

HTML代码：

<textarea type="text" id="normal" rows="15" cols="80" placeholder="Normal text goes in here..."></textarea>
<textarea type="text" id="theiftalk" rows="15" cols="80" placeholder="Theif Talk text goes out here..."></textarea>
<br>
<button id="translateBtn">translate</button>

最佳答案

由于您没有从函数中返回任何内容，因此明确返回了undefined。您已经从函数返回了值。另外，theifTalk是元素本身，您应该从中获取值：

function b() {
  theifTalk.value = theifTalk.value + "bob";
  return theifTalk.value;
}

您还应该将值设置回theifTalk：

theifTalk.value = b().repeat(bCount.length);

const theifTalk = document.getElementById('theiftalk');
const normal = document.getElementById('normal');
const translateBtn = document.getElementById('translateBtn');

translateBtn.onclick = function() {
  translate();
}
function translate() {
  if (normal.value.includes("b")) {
    var bCount = normal.value.match(/b/g)||[].length;
    theifTalk.value = b().repeat(bCount.length);
  }
}

function b() {
  theifTalk.value = theifTalk.value + "bob";
  return theifTalk.value;
}

<textarea type="text" id="normal" rows="15" cols="80" placeholder="Normal text goes in here..."></textarea>
<textarea type="text" id="theiftalk" rows="15" cols="80" placeholder="Theif Talk text goes out here..."></textarea>
<br>
<button id="translateBtn">translate</button>