log(outputString1); console.log(outputString2); If we call charAt(0), this will copy the character W from the original string, inputString into outputString1. The above code will give you the below output.Output:"W " "J" Get the First Character of a String Using substring() in ...
var character = carname[7]; 字符串的索引从 0 开始,这意味着第一个字符索引值为[0],第二个为[1],以此类推。 实例 constname="RUNOOB"; let letter=name[2]; document.getElementById("demo").innerHTML=letter; 尝试一下 » 你可以在字符串中使用引号,字符串中的引号不要与字符串的引号相同: 实例...
getClass() 返回一个 JavaObject 的 JavaClass。 isFinite() 检查某个值是否为有穷大的数。 isNaN() 检查某个值是否是数字。 Number() 把对象的值转换为数字。 parseFloat() 解析一个字符串并返回一个浮点数。 parseInt() 解析一个字符串并返回一个整数。 String() 把对象的值转换为字符串。 unescape()...
function getThis()( console.log(this) } getThis(); //returns Window {postMessage: ƒ, blur: ƒ, focus: ƒ, close: ƒ, frames: Window, ...} Listing 5-2Get the Current Context of a Function in the Global Scope 代码中调用函数的地方称为执行上下文。执行上下文决定了this 的值。注...
In this tutorial, we are going to learn about how to get the first character of a string in JavaScript. reactgo.com recommended courseJavaScript - The Complete Guide 2023 (Beginner + Advanced) Getting the first character To get the first character of a string, we can use the charAt() met...
string – 如果变量是 String 类型的 object – 如果变量是一种引用类型或 Null 类型的 3)通过instanceof 运算符解决引用类型判断问题 4)null 被认为是对象的占位符,typeof运算符对于null值返回“object”。 5)原始数据类型和引用数据类型变量在内存中的存放如下: ...
The first character of a string has an index of 0, and the last has an index of str.length - 1. Get the last character of a string using bracket notation You can also use the bracket notation ([]) to get the last character of a string: const str = 'JavaScript' const lastChar =...
JavaScript String Methods NameDescription at()Returns an indexed character from a string charAt()Returns the character at a specified index (position) charCodeAt()Returns the Unicode of the character at a specified index codePointAt()Returns the Unicode value at an index (position) in a string ...
* @returns {string} - The middle character(s) of the string. */ function test(text) { // Get the length of the input string var text_len = text.length; // Check if the length of the string is odd or even if (text_len % 2 != 0) { // Calculate the start index for odd-...
“Control character in string: {a}.” : “在字符串中出现了Control的字符”, “Avoid \\’.” : “避免 \\”, “Avoid \\v.” : “避免 \\v”, “Avoid \\x-.” : “避免 \\x-”, “Bad escapement.” : “错误的转义字符”, ...