JavaScript是一种解释执行的脚本语言,是一种动态类型、弱类型、基于原型的语言,内置支持类型,它遵循ECMAScript标准。它的解释器被称为JavaScript引擎,为浏览器的一部分,广泛用于客户端的脚本语言,主要用来给HTML增加动态功能。 几乎所有主流的语言都可以编译为JavaScript,进而能够在所有平台上的浏览器中执行,这也体现了Java...
firstElementChild,指向第一个 Element 类型的子元素(Element版firstChild); lastElementChild,指向最后一个 Element 类型的子元素(Element版lastChild); previousElementSibling , 指向前一个Element类型的同胞元素(Element版previousSibling); nextElementSibling,指向后一个 Element 类型的同胞元素(Element版nextSibling)。
摘要:一般来说,一个函数是可以通过外部代码调用的一个“子程序”(或在递归的情况下由内部函数调用)。像程序本身一样,一个函数由称为函数体的一系列语句组成。值可以传递给一个函数,函数将返回一个值。 在 JavaScript中,函数是头等(first-class)对象,因为它们可以像任何其他对象一样具有属性和方阅读全文 ...
Using Regular Expression to Find & Remove the First Character of a String: By using a regular expression pattern with replace() we can do find and replace in one operation. Consider the following for example, to remove the first comma in a string: const str = ',foobar...
The first character is in position 0, the second in 1, and so on. For a tutorial about Strings, read ourJavaScript String Tutorial. String Properties and Methods Normally, strings like "John Doe", cannot have methods or properties because they are not objects. ...
How can you remove the last character from a string?The simplest solution is to use the slice() method of the string, passing 2 parameters. THe first is 0, the starting point. The second is the number of items to remove. Passing a negative number will remove starting from the end. ...
Countable - A JavaScript function to add live paragraph-, word- and character-counting to an HTML element. card - Make your credit card form better in one line of code. stretchy - Form element autosizing, the way it should be. analytics - A lightweight, extendable analytics library designed...
unsafe_undefined (default: false)— substitute void 0 if there is a variable named undefined in scope (variable name will be mangled, typically reduced to a single character) unused (default: true)— drop unreferenced functions and variables (simple direct variable assignments do not count as ref...
因为局部变量只作用于函数内,所以不同的函数可以使用相同名称的变量。 局部变量在函数开始执行时创建,函数执行完后局部变量会自动销毁。 JavaScript全局变量 变量在函数外定义,即为全局变量。 全局变量有全局作用域: 网页中所有脚本和函数均可使用。 var carName = " Volvo"; ...
要深入了解关于字符编码的内容,推荐 Joel Spolsky 写的博客文章:“The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)”。 另一个有用的资源是 Mathias Bynens 的博文:“JavaScript’s Internal Character Encoding: UCS-2 or UTF-16?