JS array to string (3 methods) and string to array (2 methods)

1: Array to string (3 methods)

It is also an array to string. What is the difference between toString(), toLocaleString(), join(), join (',')?

JavaScript allows the conversion between arrays and strings. The Array method object defines three methods that can convert an Array into a string, as shown in the table.

Array method	explain
toString()	Converts an array to a string
toLocaleString()	Converts an array to a locally agreed string
join()	Concatenate array elements to build a string

1: The join() method is used to put all the elements in the array into a string

Elements are separated by a specified separator

Delimiter specified by join()	explain
join()	It can be understood as directly changing into a string, separated by commas by default
join(' ')	Empty connection
join(',') or join('-') or join('.)	The comma in the middle is added manually, or it can be changed to something else, such as- You can wait

// join()
var a= ["00", "01", "02", "03", "04"]
var b=  a.join()      
console.log(b)
console.log( typeof b)
//Print results 00,01,02,03,04

// join('')
var a= ["00", "01", "02", "03", "04"]
var b=  a.join('')      
console.log(b)
console.log( typeof b)
//Print result 0001020304

// join(',')
var a= ["00", "01", "02", "03", "04"]
var b=  a.join(',')      
console.log(b)
console.log( typeof b)
//Print results 00,01,02,03,04

perhaps

// join('-')
var a= ["00", "01", "02", "03", "04"]
var b=  a.join('-')      
console.log(b)
console.log( typeof b)
//Print result 00-01-02-03-04

perhaps
// join('!')
var a= ["00", "01", "02", "03", "04"]
var b=  a.join('!')      
console.log(b)
console.log( typeof b)
//Print result 00! 01! 02! 03! 04

2: The toString() method converts a logical value into a string and returns the result

var a= ["00", "01", "02", "03", "04"]
var c = a.toString();  //Convert array to string
console.log(c)
console.log(typeof c);  //Returns a string, indicating that it is a string type
//Print results 00,01,02,03,04

The toString() method cannot specify a delimiter, but we can specify a replacement through the replace() method

var a= ["00", "01", "02", "03", "04"]
var f = a.toString().replace(/,/gi,'-')
console.log(f)
//Print result: 00-01-02-03-04

3: toLocaleString()

Converts an array to a locally agreed string

var a= ["00", "01", "02", "03", "04"]
var e = a.toLocaleString();  
console.log(e)
console.log(typeof e);  
//Print result: 00,01,02,03,04

demo

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <script src="http://code.jquery.com/jquery-1.8.0.min.js"></script>
        <title></title>
    </head>
    <body>
    </body>
    <script type="text/javascript">
        var a= ["00", "01", "02", "03", "04"]
        
        //1:
        var b=  a.join(',')      
        console.log(b)
        console.log( typeof b)
        //2:
        var c = a.toString();  //Convert array to string
        console.log(c)
        console.log(typeof c);  //Returns a string, indicating that it is a string type
        
        //3:
        var d = a.join();  //Convert array to string
        console.log(d)
        console.log(typeof d);  //Returns a string, indicating that it is a string type
		
		//4:
		var e = a.toLocaleString();  //Convert array to string
		console.log(e)
		console.log(typeof e);  //Returns a string, indicating that it is a string type
        
    </script>
</html>

2: String to array (2 methods)

String method	explain
split() method	Converts a string to an array
Extended operator (...)	Extension operators in es6

String to array

1: The split () method is used to split a string into an array of strings

It is also used to divide a string into string arrays. What is the difference between split(','), split(), split('')?

split() method	explain
split(',')
split()	It can be understood as directly changing into a string, separated by commas by default
split('') empty string	Each character is divided

var arr = 'aa,bb,cc,dd'
var newStr = arr.split(',')
console.log(newStr) 
// Print result: ["aa", "bb", "cc", "dd"]

var arr = 'aa,bb,cc,dd'
var newStr = arr.split()
console.log(newStr)
// Print result: [aa,bb,cc,dd]

If an empty string ("") is used as a separator, each character in the stringObject will be split

var arr = 'aa,bb,cc,dd'
var newStr = arr.split('')
console.log(newStr) 
//Print results: [a "," a "," B "," B "," C "," C "," d "," D]

2: Extension operators in es6

var arr = 'aa,bb,cc,dd'
var newStr = [...arr]
console.log(newStr) 
//Print results ["a", "a", "B", "B", "C", "C", "d", "d"]

The above are several methods to convert js array and string ~ ∠ (° ω °)／ ~

Added by l_evans on Tue, 18 Jan 2022 06:12:10 +0200

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