我们有一项必须完成的 JavaScript 作业。我们必须构建一个句子生成器。当我在 Chrome 中运行此程序时，单击按钮时没有任何反应。当我检查控制台日志时，它显示 Uncaught ReferenceError: mySubject is not Defined. 我以为我已经在 element1.onclick 函数中定义了它？
这是我到目前为止的代码:
<body>
<div id="container">
<div id="buttons">
<button id="btn1">Generate subject</button>
<input name="subject" type="text" id="subject"
/>
<button id="btn2">Generate verb</button>
<input name="verb" type="text" id="verb" />
<button id="btn3">Generate adjective</button>
<input name="adj" type="text" id="adj" />
<button id="btn4">Generate object</button>
<input name="object" type="text" id="object" />
</div>
<!--buttons closing div-->
<div>
<p id="output">asjkldhfahfjasf;d</p>
</div>
<!--output closing div-->
</div>
<!--container closing div-->
<script>
var subject = new Array("Mel Gibson", "Optimus-Prime", "The Cat-lady", "The student", "My Dentist");
var verb = new Array("licks", "pets", "hugs", "stabs", "eats");
var adj = new Array("fat", "ugly", "delicious", "redundant", "hopeless");
var object = new Array("cat", "bacon-strip", "dog-house", "bigmac", "hobo");
var element1 = document.getElementById("btn1");
var element2 = document.getElementById("btn2");
var element3 = document.getElementById("btn3");
var element4 = document.getElementById("btn4");
element1.onclick = function() {
mySubject = subject[Math.random() * subject.length]
};
element2.onclick = function() {
myVerb = verb[Math.random() * verb.length]
};
element3.onclick = function() {
myAdj = adj[Math.random() * adj.length]
};
element4.onclick = function() {
myObject = object[Math.random() * object.length]
};
document.getElementById("output").innerHTML = mySubject + myVerb + " the" + myAdj + myObject + ".";
</script>
</body>
我开始迷失方向，不知道该怎么做，这只是我遇到的众多问题之一。
编辑:
所以我得到了一些关于 Javascript 的帮助，现在除了输出之外一切都正常。我希望它输出到输出 div，但它没有输出任何内容。这是我现在的代码:
<h1>The Amazing Fantastical Sentence Generator!</h1>
<h4>Have hours of fun with your imaginary friends!</h4>
</div><!--title closing div-->
<div id="buttons">
<button id="btn1">Generate subject</button>
<input name="subject" type="text" id="insubject"/>
<button id="btn2">Generate verb</button>
<input name="verb" type="text" id="verb"/>
<button id="btn3">Generate adjective</button>
<input name="adj" type="text" id="adj"/>
<button id="btn4">Generate object</button>
<input name="object" type="text" id="object"/>
<div >
<p id="output"></p>
</div><!--output closing div-->
</div><!--container closing div-->
<script>
var subject=new Array("Mel Gibson", "Optimus-Prime", "The Cat-lady", "The student", "My Dentist");
var verb=new Array("licks", "pets", "hugs", "stabs", "eats");
var adj=new Array("fat", "ugly", "delicious", "redundant", "hopeless");
var object=new Array("cat", "bacon-strip", "dog-house", "bigmac", "hobo");
var element1=document.getElementById("btn1");
var element2=document.getElementById("btn2");
var element3=document.getElementById("btn3");
var element4=document.getElementById("btn4");
element1.onclick=function() {document.getElementById('insubject').value=subject[Math.floor(Math.random()*(subject.length))];}
element2.onclick=function(){document.getElementById('verb').value=verb[Math.floor(Math.random()*(verb.length))];}
element3.onclick=function(){document.getElementById('adj').value=adj[Math.floor(Math.random()*(adj.length))];}
element4.onclick=function(){document.getElementById('object').value=object[Math.floor(Math.random()*(object.length))];}
document.getElementById("output").innerHTML= document.getElementById("insubject").value + document.getElementById("verb").value + " the" + document.getElementById("adj").value + document.getElementById("object").value + ".";
</script>
</body>
</html>
最佳答案
在函数内部声明的变量是这些函数的本地，这意味着您不能在这些函数之外使用它们。尝试将变量声明为函数外部的全局变量。
关于Javascript 输出未显示，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15247856/