`string text` `string text line 1 string text line 2` `string text ${expression} string text` tag`string text ${expression} string text` 自动分号补全 一些JavaScript 语句必须用分号结束,所以会被自动分号补全 (ASI) 影响: 空语句 let、const、变量声明 import、export、模块定义 表达式语句 debugger...
It's a JavaScript convention to use camel case for variable names with more than one word; for example, the variable className.Console messageAs a web developer, you can create hidden messages that aren't visible on your webpage, but that you can read in the Developer Tools in the ...
constwrongType=TypeError("Wrong type given, expected number");wrongType.message;// "Wrong type given, expected number"wrongType.name;// "TypeError" Firefox 还实现了一些非标准属性,如 columnNumber、filename 和 lineNumber。 3 JavaScript 中的错误类型 JavaScript 中有很多错误类型,包括: Error EvalError...
One-Way Data Binding: Changes in the model or state automatically update the corresponding UI elements. However, changes made in the UI do not automatically update the model. React uses one-way data binding. Routing Most frameworks include built-in routing capabilities/ solutions. This enables dev...
hidden.bs.tab (on the previous active tab, the same one as for the hide.bs.tab event) shown.bs.tab (on the newly-active just-shown tab, the same one as for the show.bs.tab event) If no tab was already active, then the hide.bs.tab and hidden.bs.tab events will not be ...
However, if you're acting from outside the window, e.g. in some test framework that creates jsdoms, you can override one or both of these using the special reconfigure() method: const dom = new JSDOM(); dom.window.top === dom.window; dom.window.location.href === "about:blank";...
hidden.bs.tab (on the previous active tab, the same one as for the hide.bs.tab event) shown.bs.tab (on the newly-active just-shown tab, the same one as for the show.bs.tab event) If no tab was already active, then the hide.bs.tab and hidden.bs.tab events will not be fired...
With destructuring, all in one line:const { firstName: first, age, city = "Paris" } = person; // That's it ! console.log(age) // 35 -- A new variable age is created and is equal to person.age console.log(first) // "Nick" -- A new variable first is created and is equal...
Figure 1-9. The Safari Error Console displays the name of the JavaScript error, the filename (and location), and the line on which Safari encountered the error. Each tab or browser window has its own error console, so if you’ve already opened the console for one tab, you need to cho...
Oneternaryoperator, whichtakes the form? x : y. It’s a terse, single-lineifstatement that chooses between two expressions, depending on the result of a third one. Operator Precedence If all operatorshad the same precedence, they would be processed in the order in which they are encountered...