String object in JavaScript methods and properties summary

String object in JavaScript methods and properties summary

String object mainly for handling text strings.

This article describes a total of 26 ways to follow-up, if any supplement will be updated at any time

Attributes

constructor

Constructor String object, the object is to create a function reference.

length

String length

prototype

String prototype object, can add properties and methods above

var a = 'abc'
a.constructor.prototype.abc = 'aaa'
a.constructor.prototype.sat = ()=> 'hello'
log(a.abc) // aaa
log(a.say()) // hello

method

charAt()

Description: Returns the character at the specified location.

Syntax: str.charAt (Location)

Code:

var str = 'hello word'
log(str.charAt(1))
// 打印 e

charCodeAt()

Description: Returns the Unicode character encoding in the location specified in.

Syntax: str.charCodeAt (Location)

代码：

var str = 'hello word'
log(str.charCodeAt(1))
// 打印 101

concat()

Description: connecting two or more strings and returns the new string.

Syntax: str.concat (str1, str2)

代码：

var str = 'aaa'
var str1 = 'bbb'
var str2 = 'ccc'
log(str.concat(str1, str2))
// 打印 aaabbbccc

fromCharCode()

Description: The Unicode character encoding into

Syntax: String.fromCharCode (65)

代码：

log(String.fromCharCode(65))
// 打印 A

indexOf()

Description: Returns a string value specifies the location of the first occurrence of the string.

Syntax: str.indexOf (string)

代码：

var str = 'hello'
log(str.indexOf('e'))
// 打印 1

includes()

Description: Find a string contains a specified substring. Return true or false

Syntax: str.includes (string)

代码：

var str = 'hello word'
log(str.includes('word'))
// 打印 true

match()

Description: Find find one or more regular expression matching.

Syntax: str.match (regular)

代码：

var str = 'aabbccdd'
log(str.match(/a/g))
// 打印 ["a", "a"]
log(str.match(/a/))
// 打印 ["a", index: 0, input: "aabbccdd"]

repeat()

Description: Specifies the number of times copy the string itself, and return to connect them together.

Syntax: str.repeat (copy number);

代码：

var str = 'abc'
log(str.repeat(3))
// 打印 abcabcabc

replace()

Description: Find matching substring in the string, the string and replacing the regular expression matching.

语法：str.replace(searchValue，newValue)

代码：

var str = 'aabbcc'
log(str.replace('b', 't'))
// 打印 aatbcc
log(str.replace(/b/g, 't'))
// 打印 aattcc

search()

Description: Find the value of regular expression matching the position.

Syntax: str.search (string)

代码：

var str = 'aabbcc'
log(str.search(/c/))
// 打印 4

slice()

Description: extracting fragments of a string, and returns the extracted part in a new string.

Syntax: slice (start, end)

代码：

var str="Hello world!"
log(str.slice(2,9))
// 打印 llo wro

split()

Description: dividing an array of strings is a string.

Syntax: str.split (string)

代码：

var str = 'hello wrod'
log(str.split(''))
// 打印 ["h", "e", "l", "l", "o", " ", "w", "r", "o", "d"]
log(str.split('lo'))
// 打印 ["hel", " wrod"]

startsWith()

Note: Check whether the string starts with substring specified. Ture or false return

Syntax: str.startsWith (string)

Code:

var str = 'hello wrod'
log(str.startsWith('hello'))
// 打印 true
log(str.startsWith('llo'))
// 打印 false

endsWith()

Note: Check whether the string ends with the substring specified. Ture or false return

Syntax: str.endsWith (string)

Code:

var str = 'hello wrod'
log(str.startsWith('hello'))
// 打印 true
log(str.startsWith('llo'))
// 打印 false

substr()

Description: Specifies the number of characters from the start index extraction string. The second parameter is the number of characters to be taken, If not a default character taken to the end, does not change the source string.

Syntax: str.substr (start, length)

Code:

var str = 'hello wrod'
log(str.substr(1, 3))
// 打印 ell
log(str.substr(1))
// 打印 ello wrod

substring()

Description: The character string between two specified index extraction. Between the character segments taken from a location to another. If the second parameter is omitted, then the substring will always return to the end of the string.

语法：string.substring(from, to)

Code:

var str = 'hello wrod'
log(str.substring(1))
// 打印 ello wrod
log(str.substring(1, 3))
// 打印 el

toLowerCase()

Description: to convert the string to lowercase.

Syntax: str.toLowerCase ()

Code:

var str = 'AAAbbbCCCdddEEE'
log(str.toLowerCase())
// 打印 aaabbbcccdddeee

toUpperCase()

Note: to convert a string to uppercase.

Syntax: str.toUpperCase ()

Code:

var str = 'AAAbbbCCCdddEEE'
log(str.toUpperCase())
// 打印 AAABBBCCCDDDEEE

trim()

Description: removing the blank on either side of the string

Syntax: str.trim ()

Code:

var str = '   AAAbbbCCCdddEEE   '
log(str.trim())
// 打印 AAAbbbCCCdddEEE

toLocaleLowerCase()

Description: According to the local host locale string converted to lowercase.

Syntax: str.toLocaleLowerCase ()

Code:

var str = 'AAAbbbCCCdddEEE'
log(str.toLocaleLowerCase())
// 打印    aaabbbcccdddeee

toLocaleUpperCase()

Description: According to the local host locale string converted to uppercase.

Syntax: str.toLocaleUpperCase ()

Code:

var str = 'AAAbbbCCCdddEEE'
log(str.toLocaleUpperCase())
// 打印 AAABBBCCCDDDEEE

valueOf()

Description: returns the original value of a string object. valueOf () method is usually performed automatically in the background by the JavaScript call, rather than explicitly in the code.

Syntax: str.valueOf ()

Code:

var str = 'AAAbbbCCCdddEEE'
log(str.valueOf())
// 打印 AAAbbbCCCdddEEE

toString()

Description: Returns a string.

Syntax: str.toString ()

Code:

var str = 'AAAbbbCCCdddEEE'
log(str.toString())
// 打印 AAAbbbCCCdddEEE

tart pads ()

Description: string from the filling head. (ES6)

Syntax: str.padStart (targetLength, string)

Code:

var str = '123'
log(str.padStart(5, '0'))
// 打印 00123

padEnd()

Description: string filled in the tail. (ES6)

Syntax: str.padEnd (targetLength, string)

Code:

var str = '123'
log(str.padEnd(5, '0'))
// 打印 12300

raw()

Description: raw () function is a template tag string, is used to obtain a measure of the original template literal string.

callSiteA template string "call site object"

...substitutionsAny optional parameter indicating the value of the interpolation expression corresponding to an arbitrary number. templateString template string.

Syntax: String.raw (callSite, ... substitutions)

Code:

var str = 'abcd'
log(String.raw`hel${str}lo`)
// 打印 helabcdlo