js switch(true){caseisSquare(shape):console.log("该形状是一个正方形。");// 失败,因为正方形也是矩形的一种!caseisRectangle(shape):console.log("该形状是一个矩形。");caseisQuadrilateral(shape):console.log("该形状是一个四边形。");break;caseisCircle(shape):console.log("该形状是一个圆形。")...
The event model in JavaScript for web pages differs from the event model for JavaScript as it is used in other environments. For example, Node.js is a very popular JavaScript runtime that enables developers to use JavaScript to build network and server-side applications. The Node.js event mod...
函数是 JavaScript 中的基本组件之一。JavaScript 中的函数类似于过程——一组执行任务或计算值的语句。但要成为函数,这个过程应该接受输入并返回与输入存在某些明显关系的输出。要使用一个函数,你必须将其定义在你希望调用它的作用域内。
switch语句对一个表达式求值,将结果与 case 子语句比较,如果匹配,则从 case 处的语句向下执行。 375 throw JavaScript, Statement, 流程控制 throw 语句用来抛出用户自定义异常。当前函数的执行将会被中止(throw之后的语句将会得不到执行),接着执行流程会转移到第一个 catch 语句块。如果在调用方函数中没有任何catch...
In contrast to Java's compile-time system of classes built by declarations, JavaScript supports a runtime system based on a small number of data types representing numeric, Boolean, and string values. JavaScript has a prototype-based object model instead of the more common class-based object mod...
For example: 3.1415926 -.123456789 -3.1E+12 .1e-23 Object literals An object literal is a list of zero or more pairs of property names and associated values of an object, enclosed in curly braces ({}). You should not use an object literal at the beginning of a statement. This will...
JavaScript has a concurrency model based on an "event loop". This model is quite different from models in other languages like C and Java.