脚本产生我找不到的错误

Question

最终目的是返回一个显示以下句子的页面

从前，有一个名为 NAME
的性别，他有一个名为 PET NAME 的宠物。

<SCRIPT language="JavaScript">

var heroGender, heroName, petType, petName;

heroGender = window.prompt('Is the hero female or male? Enter F or M', 'F');

heroName = window.prompt('What is the hero\'s name?','');

petType = window.prompt('What type of pet does the hero have?','');

petName = window.prompt('What is name of the pet?','');

  document.write('Once upon a time there was a ');

if (heroGender == ('F'))
{
    document.write('girl');
}
else 
{
    document.write('boy');
}

document.write('Once upon a time there was a ' + heroGender + ' named ' + heroName '.''<BR>' +
                                    heroName + ' had a ' + petType + ' called ' + petName + '.');

</SCRIPT>

Answer 1

在等待书籍时！

从 Mozilla 开发者中心！

示例：

示例

固定版本

document.write(
    'Once upon a time there was a ' + heroGender + 
    ' named ' + heroName  + '.' + '<BR>' + heroName + 
    ' had a ' + petType + ' called ' + petName + '.');

损坏的版本

您缺少 + 符号。

document.write(
    'Once upon a time there was a ' + heroGender + 
    ' named ' + heroName /* + */ '.' /* + */ '<BR>' + heroName + 
    ' had a ' + petType + ' called ' + petName + '.');

尝试使用

• Firefox 和 Firebug 及其控制台选项卡（按 F12）
• IE9 和控制台中的构建（按 F12）。确保控制台打开然后刷新）。
• Chrome 和控制台中的构建（按 Ctrl+Shift+J）

监视任何错误消息。

如果这太费力，那么请尝试

window.onerror = function(e) {
  alert(e.message);
}

这是一个“改进的”更符合标准的版本。 示例链接！

HTML：

<label> Your Hero's gender </label><input id="heroGender"/><br/>
<label> Your Hero's name </label><input id="heroName"/><br/>
<label> Your Hero's pet type </label><input id="petType"/><br/>
<label> Your Hero's pet name </label><input id="petName"/><br/>
<button> Make me a hero! </button>
<div id="output"></div>

JavaScript：

// make your hero when you press the button
document.getElementsByTagName("button")[0].addEventListener("click", function() {
    // get all the values from the text boxes
    var gender = document.getElementById("heroGender").value,
        name = document.getElementById("heroName").value,
        petType = document.getElementById("petType").value,
        petName = document.getElementById("petName").value;

    // set the text on your output.
    document.getElementById("output").textContent = 
        "Once upon a time there was a " + gender +
        " named " + name + ". " + name + " had a pet " + 
        petType + " called " + petName;


}, false);

上面的代码在 IE8 或更低版本下会崩溃:(。让 JavaScript 跨浏览器工作是一件痛苦的事。

所以你可以阅读浏览器的文档

• Firefox 的 MDN
• Microsoft JavaScript 文档 和 HTML 文档

但这些文档不容易阅读或导航。跨浏览器脚本编写的一个很好的视觉指南是 visibone BrowserBook。

它将显示跨浏览器支持（红色是 firefox，蓝色是 IE）：

给它几个月的时间，您就会知道如何舒适地使用所有这些。

Answer 2

我认为您的最终 document.write 中有一些拼写错误。您在 HeroName 之后缺少一个“+”...并且您有一些重复的 document.writes。

我认为这应该是您的最终代码：

var heroGender, heroName, petType, petName;
heroGender = window.prompt('Is the hero female or male? Enter F or M', 'F');
heroName = window.prompt('What is the hero\'s name?','');
petType = window.prompt('What type of pet does the hero have?','');
petName = window.prompt('What is name of the pet?','');

if (heroGender == ('F')) { heroGender ='girl'; } else { heroGender = 'boy'; }
document.write('Once upon a time there was a ' + heroGender + ' named ' + heroName + '. ' + heroName + ' had a ' + petType + ' called ' + petName + '.');

Answer 3

此行中有一个语法错误：

document.write('Once upon a time there was a ' + heroGender + ' named ' + heroName '.''<BR>' + heroName + ' had a ' + petType + ' called ' + petName + '.');

具体而言，此处：

heroName '.''<BR>' + heroName

如果将其更改为此，则应该按预期工作：

document.write(' named ' + heroName + ' who had a ' + petType + ' called ' + petName + '.');

请注意，我还删除了该短语第一部分中的冗余，因为您已经将其包含在“if”之前“F”，然后是“女孩””声明。

Answer 4

太多引号和缺少的加号

Error: missing ) after argument list
Source File: http://fiddle.jshell.net/_display/
Line: 41, Column: 83
Source Code:
document.write('Once upon a time there was a ' + heroGender + ' named ' + heroName '.''<BR>' + 

应该是

document.write(' named ' + heroName + '.<BR>' + 
heroName + ' had a ' + petType + ' called ' + petName + '.');

http://jsfiddle.net/mplungjan/zHGsD/

Answer 5

document.write('Once upon a time there was a ' + heroGender + ' named ' + heroName **+** '.' **+** '<BR>' +
                                    heroName + ' had a ' + petType + ' called ' + petName + '.');

我通过添加包裹在 ** 中的两个 + 来运行它

Answer 6

问题出在你的最后一行。更正如下

document.write('Once upon a time there was a ' + heroGender + ' named ' + heroName + '.' + '<BR>' + heroName + ' had a ' + petType + ' called ' + petName + '.');