478

How can I convert a string to a JavaScript array?

Look at the code:

var string = "0,1";
var array = [string];
alert(array[0]);

In this case alert shows 0,1. If it where an array, it would show 0. And if alert(array[1]) is called, it should pop-up 1

Is there any chance to convert such string into a JavaScript array?

4
  • 1
    Depending why you want this, strings and arrays are already very similiar (i.e. string[0] === '0' in your question), in most cases you can treat a string as an array of chars and use array methods on it. Commented Nov 7, 2012 at 15:19
  • 1
    @PaulS.: That will fail in IE8 and lower. Commented Nov 7, 2012 at 16:00
  • 1
    possible duplicate of convert javascript comma separated string into an array Commented Apr 8, 2014 at 3:57
  • 1
    Best practice for support all types of strings. See here stackoverflow.com/a/32657055/2632619 Commented Sep 18, 2015 at 16:43

17 Answers 17

822

For simple array members like that, you can use JSON.parse.

var array = JSON.parse("[" + string + "]");

This gives you an Array of numbers.

[0, 1]

If you use .split(), you'll end up with an Array of strings.

["0", "1"]

Just be aware that JSON.parse will limit you to the supported data types. If you need values like undefined or functions, you'd need to use eval(), or a JavaScript parser.


If you want to use .split(), but you also want an Array of Numbers, you could use Array.prototype.map, though you'd need to shim it for IE8 and lower or just write a traditional loop.

var array = string.split(",").map(Number);
Sign up to request clarification or add additional context in comments.

12 Comments

Also be aware that JSON.parse(); is not available in IE6, IE7. I think in this case the String.split(','); is easier.
@scunliffe: True, a shim would be needed, or one could take the jQuery approach to shim it var array = (new Function("return [" + string + "];"))(). Using .split() is alright if Numbers aren't needed, otherwise you'd need to map the result.
@I Hate Lazy This doesnt support object string.see here stackoverflow.com/a/32657055/2632619
@FarzadYZ Be careful with that (using eval). If the array contains values from client side input this will be insecure.
@Wilt Actually eval is always a security concern
|
165

Split it on the , character;

var string = "0,1";
var array = string.split(",");
alert(array[0]);

Comments

106

This is easily achieved in ES6;

You can convert strings to Arrays with Array.from('string');

Array.from("01")

will console.log

['0', '1']

Which is exactly what you're looking for.

8 Comments

This is awesome. I moved my code from JSON.parse to Array.from as am using ES6. Thank you Ray Kim
This is NOT supported in any version of IE. be careful
But Array.from("0, 1, 233") will return ["0", ",", " ", "1", ",", " ", "2", "3", "3"], what if I want [0, 1, 233] ?
bad solution! more info seeing https://github.com/gildata/RAIO/issues/116#issuecomment-325901359
This is converting every single character as an array element. But we need only comma separated strings to be array elements. So not a valid solution.
|
81

If the string is already in list format, you can use the JSON.parse:

var a = "['a', 'b', 'c']";
a = a.replace(/'/g, '"');
a = JSON.parse(a);

Comments

30

Convert all type of strings

var array = (new Function("return [" + str+ "];")());



var string = "0,1";

var objectstring = '{Name:"Tshirt", CatGroupName:"Clothes", Gender:"male-female"}, {Name:"Dress", CatGroupName:"Clothes", Gender:"female"}, {Name:"Belt", CatGroupName:"Leather", Gender:"child"}';

var stringArray = (new Function("return [" + string+ "];")());

var objectStringArray = (new Function("return [" + objectstring+ "];")());

JSFiddle https://jsfiddle.net/7ne9L4Lj/1/

Result in console

enter image description here

Some practice doesnt support object strings

- JSON.parse("[" + string + "]"); // throw error

 - string.split(",") 
// unexpected result 
   ["{Name:"Tshirt"", " CatGroupName:"Clothes"", " Gender:"male-female"}", "      {Name:"Dress"", " CatGroupName:"Clothes"", " Gender:"female"}", " {Name:"Belt"",    " CatGroupName:"Leather"", " Gender:"child"}"]

2 Comments

Great function I also use it but unfortunately it does NOT work for strings or symbols: like e.g. "0,s" any ideas how to fix that?
@sqp_125 try 0,'s' ?
23

For simple array members like that, you can use JSON.parse.

var listValues = "[{\"ComplianceTaskID\":75305,\"RequirementTypeID\":4,\"MissedRequirement\":\"Initial Photo Upload NRP\",\"TimeOverdueInMinutes\":null}]";

var array = JSON.parse("[" + listValues + "]");

This gives you an Array of numbers.

now you variable value is like array.length=1

Value output

array[0].ComplianceTaskID
array[0].RequirementTypeID
array[0].MissedRequirement
array[0].TimeOverdueInMinutes

Comments

20

You can use split

Reference: http://www.w3schools.com/jsref/jsref_split.asp

"0,1".split(',')

Comments

19

Another option using the ES6 is using Spread syntax.

var convertedArray = [..."01234"];

var stringToConvert = "012";
var convertedArray  = [...stringToConvert];
console.log(convertedArray);

1 Comment

Awesome! Along with Array.from answer they should be the only answers for ES6 solutions.
12

use the built-in map function with an anonymous function, like so:

string.split(',').map(function(n) {return Number(n);});

[edit] here's how you would use it

var string = "0,1";
var array = string.split(',').map(function(n) {
    return Number(n);
});
alert( array[0] );

5 Comments

This is the most generally applicable answer. JSON can not be used for arbitrary delimiters (e.g. tab, space, etc)
This won't work when your array values are string values that possible have a comma inside. For example: "123, 'a string with a , comma', 456". You could use a more complex regex to handle such cases correctly (for example something like suggested here).
@Wilt well no it wouldn't, but yeah you could use regex to fix that
I didn't mean to criticize your answer, but I wrote this because I used your solution and ran into this issue myself. Thought of leaving the comment for others possibly running into similar problems.
Could be shortened as follows string.split(',').map(Number)
6

More "Try it Yourself" examples below.

Definition and Usage The split() method is used to split a string into an array of substrings, and returns the new array.

Tip: If an empty string ("") is used as the separator, the string is split between each character.

Note: The split() method does not change the original string.

var res = str.split(",");

Comments

5

I remove the characters '[',']' and do an split with ','

let array = stringObject.replace('[','').replace(']','').split(",").map(String);

Comments

5

You can use javascript Spread Syntax to convert string to an array. In the solution below, I remove the comma then convert the string to an array.

var string = "0,1"
var array = [...string.replace(',', '')]
console.log(array[0])

Comments

2

Split (",") can convert Strings with commas into a String array, here is my code snippet.

    var input ='Hybrid App, Phone-Gap, Apache Cordova, HTML5, JavaScript, BootStrap, JQuery, CSS3, Android Wear API'
    var output = input.split(",");
    console.log(output);

["Hybrid App", " Phone-Gap", " Apache Cordova", " HTML5", " JavaScript", " BootStrap", " JQuery", " CSS3", " Android Wear API"]

Comments

2

var i = "[{a:1,b:2}]",
    j = i.replace(/([a-zA-Z0-9]+?):/g, '"$1":').replace(/'/g,'"'),
    k = JSON.parse(j);

console.log(k)

// => declaring regular expression

[a-zA-Z0-9] => match all a-z, A-Z, 0-9

(): => group all matched elements

$1 => replacement string refers to the first match group in the regex.

g => global flag

Comments

2

Regexp

As more powerful alternative to split, you can use match

"0,1".match(/[^,]+/g)

let a = "0,1".match(/[^,]+/g)

console.log(a);

2 Comments

let a = "a,b".match(/\d+/g) => undefined . This solution fails if one uses words, one would have to adjust the regex I guess
@JosePaez you are right - I update answer
0

Example using Array.filter:

var str = 'a,b,hi,ma,n,yu';

var strArr = Array.prototype.filter.call(str, eachChar => eachChar !== ',');

Comments

-1

Why don't you do replace , comma and split('') the string like this which will result into ['0', '1'], furthermore, you could wrap the result into parseInt() to transform element into integer type.

it('convert string to array', function () {
  expect('0,1'.replace(',', '').split('')).toEqual(['0','1'])
});

Comments

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.