Undefined Behavior,即未定义的行为,指程序不可预测的执行效果,一般由错误的代码实现引起。出于效率、兼容性等多方面原因,语言标准不便于定义错误程序的明确行为,而是将其统称为“未定义”的行为,可以是崩溃,也可以是非预期的任意表现,有些问题在编译器和执行环境的特殊处理下也可能不会造成实质性的危害,但不...
1、1undefined是指页面出现了未知错误的原因的2看一下页面源码，如果源码上也是undefined那就说明页面本来就是这样，如果源码的这部分是js代码，就说明js代码使用的数据有问题3提示undefined一般是在开发网站的时候定义。2、undefined在计算机中是指没有找到或没有的意思，例如某个用户某个操作没有被获取到...
Some languages such as C/C++ define many constructs as undefined behavior, while other languages, for example Java, have less undefined behavior [7]. But the existence of unde- fined behavior in higher-level languages such as Java shows this trade-off is not limited to low-level system ...
我曾经提到过几点:Clang 静态分析器、Klee 项目、-fcatch-undefined-behavior 选项是追踪一些此类错误的有用工具,但问题是这些并不像编译器一样被广泛使用,所以任何可以直接在编译器里动的手脚都能提供比那些工具里做同样事多得多的好处。不过记住,编译器受限于没有动态信息,编译时间也不能拖得太长。 Clang 拯救世界...
configure.in:9072: error: possibly undefined macro: AC_OUTPUT_SUBDIRS configure:13028: error: possibly undefined macro: AS_MESSAGE_LOG_FD 问题描述: 使用autoconf命令或者autoreconf命令生成configure配置脚本文件时,复制解压后的项目中会出现宏未定义的问题。执行autoreconf命令,autoreconf会去调用configure.in和aclo...
undefined是一个特殊值，通常用于指示变量尚未赋值。对未定义值的引用返回特殊值。其实大多数计算机语言，只有一个表示"无"的值，比如，C语言的NULL，Java语言的null，Python语言的None，Ruby语言的nil。undefined 英 [ˌʌndɪˈfaɪnd] 美 [ˌʌndɪ&#...
MediaStoreMatchBehavior MediaStorePickImagesTab MediaType MessageBoxType MmsSmsErrorType MmsSmsProtocol NicknameDataKind OpenableColumns OrganizationDataKind PhoneDataKind PhoneticNameStyle PhotoSupport QueriesProjection QuickContactMode RelationDataKind RemindersMethod ScreenBrightness SearchesProjection SearchRecentSuggesti...
BatchCheckIn Battery BDCModelResource BDCModelTemplate Behavior BehaviorEditor BevelJoint BI Bidirectional Binary BinaryFile BinaryRegistryValue Binding BindingNavigator BindingSource Bing BIOS Blank BlankApplication BlankFile BlankPhone BlankWebSite Blazor BlendAboutBoxBackground BlendPhone BlendPhonePanorama ...
C++ Standard does not standartise any behavior, giving compiler ability to generate efficient code (say by caching values). In some languages order is standartised (JAVA) in some not. TL;DR: standard says so. Jun 8, 2014 at 1:10am ...
Page sits and spins, trying to load forever, only message is in browser developer tools console see: "Uncaught TypeError: Cannot read properties of undefined (reading 'load') for index.html at (index):206:30" To Reproduce Steps to reproduce the behavior: ...