文地址:http://blog.163.com/benben_long/blog/static/199458243201481102257544/ 本文就自己编程时候遇到的一个问题,简要描述一下,并提出解决的方法: 出错信息:The final local variable xxx cannot be assigned, since it is defined in an enclosing type“,其中xxx是一个局部变量名 首先这是一个java编译时的错误,翻译成中文是:不可变的局部变量…

Putting the keyword static in front of a local variable declaration creates a special type of variable, a so-called static local variable. This variable keeps its value even after the method ends. The next time you call this method, the variable isn’…

将公共引入的文件放到common.jsp中,其他页面引入该jsp即可使用 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.g…

现有三个页面 " include.jsp " " a.jsp " " b.jsp " 页面代码如下 首先是a.jsp <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath…

Swift is a type-safe language. A type safe language encourages you to be clear about the types of values your code can work with. If part of your code requires a String, you can’t pass it an Int by mistake. Because Swift is type safe, it performs typ…

Type inference refers to the automatic detection of the data type of an expression in a programming language. Type inference is the ability to automatically deduce, either partially or fully, the type of an expression at compile time. The compiler is…

这个问题很囧,在外面定义了一个变量 xxx ,然后在python的一个函数或类里面引用这个变量,并改变它的值,结果报错local variable 'xxx' referenced before assignment,代码如下: xxx = 23 def PrintFileName(strFileName): if xxx == 23: print strFileName xxx = 24 PrintFileName("file") 错误的意思就是xxx这个变量在引用前还没有定义,这上…

Following code explain how 'global' works in the distinction of global variable and local variable. var = 'Global Variable' print(var) def func1(): var = 'Local Variable' print(var) def func2(): print(var) def func3(): global var print (var) var = 'G…

本變數型態(Variable Type): 類 別 符號位元 位元組(bytes) 表 示 法 數 值 範 圍 整 數 有 2 int(short) -32768~0~>32767 4 long -2147483648~0~2147483647 無 2 unsigned int 0~65535 2 unsigned short 0~65535 4 unsigned long 0~4294967295 浮點數 有 4 float 10^ -38~0~10^38 8 double 10^ -308~…

问题:程序报错:local variable 'e' referenced before assignment 解决:遇到这样的问题,说明你在声明变量e之前就已经对其进行了调用,定位到错误的地方,对变量进行重新的声明 通常这样的问题对于python的程序员来说都是因为习惯了python2的语法,转移到python3中时,出现的错误.在Python3中,异常对象无法在异常块作用域外访问.(原因是在垃圾收集器运行且从内存中清理引用之前会在内存栈帧中保存一个引用周期)通常参考下面这个例子来做异常处理:…