JavaScript String 参考

JavaScript 字符串

JavaScript 字符串存储一系列字符，例如 "John Doe"。

字符串可以是双引号或单引号内的任何文本：

let carName1 = "Volvo XC60";
let carName2 = 'Volvo XC60';

亲自试一试 »

字符串索引从零开始：

第一个字符位于位置 0，第二个字符位于位置 1，依此类推。

有关字符串的教程，请阅读我们的JavaScript 字符串教程。

字符串属性和方法

通常，像"John Doe"这样的字符串不能有方法或属性，因为它们不是对象。

但对于 JavaScript，方法和属性也可用于字符串，因为 JavaScript 在执行方法和属性时将字符串视为对象。

JavaScript 字符串方法

Name	Description
charAt()	Returns the character at a specified index (position)
charCodeAt()	Returns the Unicode of the character at a specified index
concat()	Returns two or more joined strings
constructor	Returns the string's constructor function
endsWith()	Returns if a string ends with a specified value
fromCharCode()	Returns Unicode values as characters
includes()	Returns if a string contains a specified value
indexOf()	Returns the index (position) of the first occurrence of a value in a string
lastIndexOf()	Returns the index (position) of the last occurrence of a value in a string
length	Returns the length of a string
localeCompare()	Compares two strings in the current locale
match()	Searches a string for a value, or a regular expression, and returns the matches
prototype	Allows you to add properties and methods to an object
repeat()	Returns a new string with a number of copies of a string
replace()	Searches a string for a pattern, and returns a string where the first match is replaced
replaceAll()	Searches a string for a pattern and returns a new string where all matches are replaced
search()	Searches a string for a value, or regular expression, and returns the index (position) of the match
slice()	Extracts a part of a string and returns a new string
split()	Splits a string into an array of substrings
startsWith()	Checks whether a string begins with specified characters
substr()	Extracts a number of characters from a string, from a start index (position)
substring()	Extracts characters from a string, between two specified indices (positions)
toLocaleLowerCase()	Returns a string converted to lowercase letters, using the host's locale
toLocaleUpperCase()	Returns a string converted to uppercase letters, using the host's locale
toLowerCase()	Returns a string converted to lowercase letters
toString()	Returns a string or a string object as a string
toUpperCase()	Returns a string converted to uppercase letters
trim()	Returns a string with removed whitespaces
trimEnd()	Returns a string with removed whitespaces from the end
trimStart()	Returns a string with removed whitespaces from the start
valueOf()	Returns the primitive value of a string or a string object

笔记

所有字符串方法都返回一个新值。

它们不会改变原始变量。

字符串 HTML 包装方法

HTML 包装器方法返回包装在 HTML 标记内的字符串。

这些不是标准方法，可能无法按预期工作。

Method	Description
anchor()	Displays a string as an anchor
big()	Displays a string using a big font
blink()	Displays a blinking string
bold()	Displays a string in bold
fixed()	Displays a string using a fixed-pitch font
fontcolor()	Displays a string using a specified color
fontsize()	Displays a string using a specified size
italics()	Displays a string in italic
link()	Displays a string as a hyperlink
small()	Displays a string using a small font
strike()	Displays a string with a strikethrough
sub()	Displays a string as subscript text
sup()	Displays a string as superscript text