应用场景:如果一个变量里面确定存放的是对象,但是还未准备好对象,可以先放个null 注意点:特殊的值,表示有值但是值为空 null 检测数据类型返回结果object,这是一个Js的bug,这个问题来自于 JavaScript 语言的早期阶段,并为了兼容性而保留了下来null属于基本数据类型,但是Js会归类为引用数据类型 引用数据类型 数组 对象...
nullptr,"flv",nullptr);avformat_new_stream(encoder_fmt_ctx,nullptr);// encoderauto encoder=avcodec_find_encoder_by_name("libx264");// CHECK_NOTNULL(encoder);AVCodecContext*encoder_ctx=avcodec_alloc_context3(encoder);// CHECK_NOTNULL(encoder_ctx);AVDictionary*encoder_options=nullptr...
// // Only Object* keys are supported, with Object::SameValue() used as the // equality operator and Object::GetHash() for the hash function. // Based on the "Deterministic Hash Table" as described by Jason Orendorff at // https://wiki.mozilla.org/User:Jorend/Deterministic_hash_tables...
// and indices so far, we can turn the {JSLoadProperty} into a map check // on the {receiver} and then just load the field value dynamically via // the {LoadFieldByIndex} operator. The map check is only necessar...
我们是袋鼠云数栈 UED 团队,致力于打造优秀的一站式数据中台产品。我们始终保持工匠精神,探索前端道路,为社区积累并传播经验价值。 本文作者:空山 什么是沙箱 沙箱即 SandBox,它是一种安全机制,用于严格控制访问资源。通过在程序中创建一个独立的运行环境,把一些来源
1.首先不要把NULL看成是null,js的关键字是区分大小写的,所以这就是一个普通的变量,而且没有声明,typeof对没有声明的变量使用是不会报错的,返回'undefined',typeof对undefined使用也是'undefined',所以两者相等 2.typeof对函数使用返回'function',class只是es6新增的语法糖,本质上还...
attr('action', null) //=> remove attribute // multiple attributes: form.attr({ action: '/create', method: 'post' })before before(content) ⇒ self Add content to the DOM before each element in the collection. The content can be an HTML string, a DOM node or an array of nodes...
pure_funcs (default: null)— You can pass an array of names and UglifyJS will assume that those functions do not produce side effects. DANGER: will not check if the name is redefined in scope. An example case here, for instance var q = Math.floor(a/b). If variable q is not used...
operator==(that); } template <class S> static inline Handle<T> Cast(Handle<S> that) { // 返回一个空的handle,即val_是null if (that.IsEmpty()) return Handle<T>(); // *that得到指向handle管理的对象的指针,转成T类型的对象,转成底层对象是类型T的handle return Handle<T>(T::Cast(*that...
uglify-js@3has a simplifiedAPIandCLIthat is not backwards compatible withuglify-js@2. Install First make sure you have installed the latest version ofnode.js(You may need to restart your computer after this step). From NPM for use as a command line app: ...