javascript 如何通过jsp表达式标签将java字符串变量传递给javascript函数？
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How to pass java string variable to the javascript function by jsp expression tag?
提问by Aditya
I want to passing a java String variable to the javascript function parameter using jsp expression tag.Below is my jsp page.
我想使用 jsp 表达式标记将 java String 变量传递给 javascript 函数参数。下面是我的 jsp 页面。
First.jsp
首先.jsp
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<script>
function stringGenerate(str){
var x = document.getElementsByTagName("input");
x[0].value = str;
}
function numberGenerate(num){
var x = document.getElementsByTagName("input");
x[1].value = num;
}
</script>
</head>
<body>
<%
String num ="1234567890";
String str = "abcdefghij";
%>
<input type="text" name="string" readonly="readonly"/>
<input type="text" name="number" readonly="readonly"/><br/><br/>
<input type="button" value="String Generate" onclick= "stringGenerate(<%=str %>)" />
<input type="button" value="Number Generate" onclick= "numberGenerate(<%=num %>)" />
</body>
</html>
When I click on the button with value "Number Generate",then the num variable value(1234567890) will display on the textbox(name="number") but when I click on the button with value "String Generate",then there is nothing display on the corresponding text box(name="string").Here both num and str are string type varible but why only num variable value is displayed on textbox and why not str variable value is displayed?
当我单击值为“Number Generate”的按钮时，num 变量值（1234567890）将显示在文本框（名称=“数字”）上，但是当我单击值为“String Generate”的按钮时，则有对应的文本框什么都不显示(name="string")。这里num和str都是字符串类型变量，但是为什么textbox上只显示num变量值，为什么不显示str变量值呢？
采纳答案by Manwal
Try using single quote 'when using string in HTML:
'在 HTML 中使用字符串时尝试使用单引号：
onclick= "stringGenerate('<%=str %>')"
^ ^
Full Code:
完整代码：
<input type="button" value="String Generate" onclick= "stringGenerate('<%=str %>')" />
回答by Dimitri Grishin
The reason is that when the page is rendered by the browser, it puts the str and num values directly in the code, so it looks like:
原因是浏览器渲染页面的时候，直接把str和num的值放在了代码中，所以看起来是这样的：
<input type="button" value="String Generate" onclick="stringGenerate(abcdefghij)"/>
The browser basically thinks you're trying to reference a Javascript variable called 'abcdefghij'.
浏览器基本上认为您正在尝试引用一个名为 .js 的 Javascript 变量'abcdefghij'。
You should add the 'chars before and after your string text to let javascript know it should use the value of that text and not search for a variable with that name.
您应该'在字符串文本之前和之后添加字符，让 javascript 知道它应该使用该文本的值，而不是搜索具有该名称的变量。
The declaration of str should look like this to make it work:
str 的声明应如下所示以使其工作：
String str = "\'abcdefghij\'";
Please note, you can't use \"to escape as this would break your code.
请注意，您不能使用\"转义，因为这会破坏您的代码。
