如何添加函式以便用戶可以輸入“p”或“a”來獲取矩形的周長或面積？-有解無憂

這是我的原始代碼，一切正常，但我需要添加第三個函式，用戶在第一個輸入（“apBox”）中輸入“a”或“p”。然后它找到矩形的周長或面積，而不是兩者兼而有之：

我哪里出錯了？

我覺得它應該是這樣的結構，但我不確定你們會怎么做？它可以作業，但不是我需要的方式，用戶可以輸入面積或周長，然后輸入長度/寬度并獲得單獨的答案。

    If () {
}
    else if () {
}
    else () {
}
    document.getElementById("message").innerHTML=(output);

function controller() {
  var type = document.getElementById("apBox").value;
  var length = document.getElementById("lengthBox").value;
  var width = document.getElementById("widthBox").value;
  var mainSolution = document.getElementById("message");
  var answer = length * width;
  var answer2 =  length    width    length    width;
  // this is where I am getting stuck, it should be an if statement, right? 
  if (type == "a") {

  }
  if (length.length > 0 && width.length > 0) {
    if (isNaN(answer) === false && isNaN(answer2) === false) {
      mainSolution.innerHTML = "Area =&nbsp"   answer   "<br>Perimeter =&nbsp"   answer2;
    } else {
      mainSolution.innerHTML = "Must Enter A Number";
    }
  } else {
    mainSolution.innerHTML = "";
  }
}

function clearText() {
  document.getElementById("message").innerHTML = ("<br>");
  document.getElementById("apBox").value = "";
  document.getElementById("lengthBox").value = "";
  document.getElementById("widthBox").value = "";
}

#main {
  background-color: #455A6F;
  border-radius: 3px;
  padding: 10px;
}

#header {
  background-color: #292A2B;
  border-radius: 3px;
  padding: 10px;
}

body {
  text-align: center;
  font-family: Montserrat;
  color: #fff;
}

a {
  color: rgb(27, 157, 218);
}

.btn1,
.btn2 {
  background-color: rgba(52, 139, 221, 0.699);
  border: #303436;
  font-family: Montserrat;
  font-size: 12px;
  color: #fff;
  letter-spacing: 2px;
  padding: 5px;
  font-size: 16px;
  font-weight: bold;
  border-radius: 5px;
  line-height: 3;
  text-decoration: none;
  box-shadow: 0 0 4px black;
  text-shadow: 0 1px 0 black;
  margin-top: 1em;
  margin-bottom: 1em;
  margin-left: 1em;
  margin-right: 1em;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  text-shadow: 1px;
  text-transform: capitalize;
  text-align: center;
}


/* This is a custom snippet I made so the footer always stays at the bottom of the page */

footer {
  position: absolute;
  right: 0;
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  padding: 2em;
  background-color: darkslategray;
  text-align: center;
  border-color: #fff;
  border-radius: 18px;
  padding: 12px;
}

.description {
  font-style: italic;
}

form {
  border-radius: 25px;
  padding: 5px;
}

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="shortcut icon" href="favicon.ico" type="image/x-icon">
  <meta name="description" content="Area of a Rectangle">
  <title>Area And Perimeter Of A Rectangle</title>
</head>

<body>
  <div id="main">
    <div id="header">
      <h1>Program 6</h1>
      <h5>Area or Perimeter</h5>
      <h6>of a Rectangle</h6>
    </div>

    <form id="myForm">
      <form id="myForm">
        <label for="apBox1">Enter A for Area or P for Perimeter:</label><br><br>
        <input type="text" id="apBox">
        <br><br>
        <label for="userInput2">Length:</label><br><br>
        <input type="text" id="lengthBox"><br><br>
        <label for="userInput3">Width:</label><br><br>
        <input type="text" id="widthBox">
      </form>

      <p id="demo">Output: </p>
      <p id="message"> <br> </p>

      <button class="btn1" type="button" onClick="controller()">Submit</button>
      <button class="btn2" type="button" onClick="clearText()">Clear</button>
  </div>
</body>

</html>

uj5u.com熱心網友回復：

將計算移至適當的if分支。

您可以為要在結果欄位中顯示的標簽添加另一個變數，因為您不再計算answer和answer2。

if (type == "a") {
    answer = length * width;
    label = 'Area';
} else if (type == "p") {
    answer = 2 * length   2 * width;
    label = 'Perimiter';
} else {
    mainSolution.innerText = "Enter either a or p";
    return;
}

完整代碼：

顯示代碼片段

function controller() {
  var type = document.getElementById("apBox").value;
  var length = document.getElementById("lengthBox").value;
  var width = document.getElementById("widthBox").value;
  var mainSolution = document.getElementById("message");
  var answer;
  var label;
  if (type == "a") {
    answer = length * width;
    label = 'Area';
  } else if (type == "p") {
    answer = 2 * length   2 * width;
    label = 'Perimiter';
  } else {
    mainSolution.innerText = "Enter either a or p";
    return;
  }
  if (length.length > 0 && width.length > 0) {
    if (!isNaN(answer)) {
      mainSolution.innerHTML = `${label} =&nbsp ${answer}`;
    } else {
      mainSolution.innerHTML = "Must Enter A Number";
    }
  } else {
    mainSolution.innerHTML = "";
  }
}

function clearText() {
  document.getElementById("message").innerHTML = ("<br>");
  document.getElementById("apBox").value = "";
  document.getElementById("lengthBox").value = "";
  document.getElementById("widthBox").value = "";
}

#main {
  background-color: #455A6F;
  border-radius: 3px;
  padding: 10px;
}

#header {
  background-color: #292A2B;
  border-radius: 3px;
  padding: 10px;
}

body {
  text-align: center;
  font-family: Montserrat;
  color: #fff;
}

a {
  color: rgb(27, 157, 218);
}

.btn1,
.btn2 {
  background-color: rgba(52, 139, 221, 0.699);
  border: #303436;
  font-family: Montserrat;
  font-size: 12px;
  color: #fff;
  letter-spacing: 2px;
  padding: 5px;
  font-size: 16px;
  font-weight: bold;
  border-radius: 5px;
  line-height: 3;
  text-decoration: none;
  box-shadow: 0 0 4px black;
  text-shadow: 0 1px 0 black;
  margin-top: 1em;
  margin-bottom: 1em;
  margin-left: 1em;
  margin-right: 1em;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  text-shadow: 1px;
  text-transform: capitalize;
  text-align: center;
}


/* This is a custom snippet I made so the footer always stays at the bottom of the page */

footer {
  position: absolute;
  right: 0;
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  padding: 2em;
  background-color: darkslategray;
  text-align: center;
  border-color: #fff;
  border-radius: 18px;
  padding: 12px;
}

.description {
  font-style: italic;
}

form {
  border-radius: 25px;
  padding: 5px;
}

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="shortcut icon" href="favicon.ico" type="image/x-icon">
  <meta name="description" content="Area of a Rectangle">
  <title>Area And Perimeter Of A Rectangle</title>
</head>

<body>
  <div id="main">
    <div id="header">
      <h1>Program 6</h1>
      <h5>Area or Perimeter</h5>
      <h6>of a Rectangle</h6>
    </div>

    <form id="myForm">
      <form id="myForm">
        <label for="apBox1">Enter A for Area or P for Perimeter:</label><br><br>
        <input type="text" id="apBox">
        <br><br>
        <label for="userInput2">Length:</label><br><br>
        <input type="text" id="lengthBox"><br><br>
        <label for="userInput3">Width:</label><br><br>
        <input type="text" id="widthBox">
      </form>

      <p id="demo">Output: </p>
      <p id="message"> <br> </p>

      <button class="btn1" type="button" onClick="controller()">Submit</button>
      <button class="btn2" type="button" onClick="clearText()">Clear</button>
  </div>
</body>

</html>

轉載請註明出處，本文鏈接：https://www.uj5u.com/net/314891.html

標籤：javascript html 数学

上一篇：我想在Groovy中決議一個.js的組態檔

下一篇：代碼排條件陳述句問題集