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  • Jsp版本的计算器(九大对象)

    只在本页面生效

    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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=UTF-8">
    <title>Insert title here</title>
    </head>
    
    <body>
    <%
    pageContext.setAttribute("abc", "shunping");
    %>
    <%
    String val=(String)pageContext.getAttribute("abc");
    out.print(val);
    %>>
    </body>
    </html>
    View Code

    eg:计算器

    caculator.jsp

    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    <form action="result.jsp" method="post">
    请输入第一个数:<input type="text" name="num1"/><br/>
    请输入第二个数:<input type="text" name="num2"/><br/>
    请选择运算符号:<select name="operator">
    <option value="+">+</option>
    <option value="-">-</option>
    <option value="*">*</option>
    <option value="/">/</option>
    </select><br/>
    <input type="submit" value="计算"/>
    </form>
    </body>
    </html>
    View Code

    result.jsp

    <%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!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=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    <%
    String num1=request.getParameter("num1");
    String num2=request.getParameter("num2");
    String operator=request.getParameter("operator");
    double d_num1=Double.parseDouble(num1);
    double d_num2=Double.parseDouble(num2);
    double res=0;
    if(operator.equals("+")){
    res=d_num1+d_num2;
    }else if(operator.equals("-")){
        res=d_num1-d_num2;    
    }else if(operator.equals("*")){
        res=d_num1*d_num2;
    }else{
        res=d_num1/d_num2;
    }
    out.print("结果是"+res);
    %>
    </body>
    </html>
    View Code

     处理输入空值或者字母等还未考虑,日后再说

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  • 原文地址:https://www.cnblogs.com/helloworld2019/p/11024398.html
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