I have a comma-separated string that I want to convert into an array, so I can loop through it.
Is there anything built-in to do this?
For example, I have this string
var str = "January,February,March,April,May,June,July,August,September,October,November,December";
Now I want to split this by the comma, and then store it in an array.
string.split(',');
var array = string.split(',');
MDN reference, mostly helpful for the possibly unexpected behavior of the limit
parameter. (Hint: "a,b,c".split(",", 2)
comes out to ["a", "b"]
, not ["a", "b,c"]
.)
Watch out if you are aiming at integers, like 1,2,3,4,5. If you intend to use the elements of your array as integers and not as strings after splitting the string, consider converting them into such.
var str = "1,2,3,4,5,6";
var temp = new Array();
// This will return an array with strings "1", "2", etc.
temp = str.split(",");
Adding a loop like this,
for (a in temp ) {
temp[a] = parseInt(temp[a], 10); // Explicitly include base as per Álvaro's comment
}
will return an array containing integers, and not strings.
"001,002,003..."
). Compare parseInt('010')
with parseInt('010', 10)
.
map
function can be used to do the integer parsing in one line: str.split(',').map(parseInt)
Hmm, split is dangerous IMHO as a string can always contain a comma. Observe the following:
var myArr = "a,b,c,d,e,f,g,','";
result = myArr.split(',');
So how would you interpret that? And what do you want the result to be? An array with:
['a', 'b', 'c', 'd', 'e', 'f', 'g', '\'', '\''] or
['a', 'b', 'c', 'd', 'e', 'f', 'g', ',']
Even if you escape the comma, you'd have a problem.
I quickly fiddled this together:
(function($) {
$.extend({
splitAttrString: function(theStr) {
var attrs = [];
var RefString = function(s) {
this.value = s;
};
RefString.prototype.toString = function() {
return this.value;
};
RefString.prototype.charAt = String.prototype.charAt;
var data = new RefString(theStr);
var getBlock = function(endChr, restString) {
var block = '';
var currChr = '';
while ((currChr != endChr) && (restString.value !== '')) {
if (/'|"/.test(currChr)) {
block = $.trim(block) + getBlock(currChr, restString);
}
else if (/\{/.test(currChr)) {
block = $.trim(block) + getBlock('}', restString);
}
else if (/\[/.test(currChr)) {
block = $.trim(block) + getBlock(']', restString);
}
else {
block += currChr;
}
currChr = restString.charAt(0);
restString.value = restString.value.slice(1);
}
return $.trim(block);
};
do {
var attr = getBlock(',', data);
attrs.push(attr);
}
while (data.value !== '')
;
return attrs;
}
});
})(jQuery);
The split() method is used to split a string into an array of substrings, and returns the new array.
var array = string.split(',');
var sampleTags = ['vinita@itsabacus.com']; console.log(sampleTags); $("#order_id").on("change", function() { var order_id = document.getElementById('order_id').value; $.ajax({url: "model/getUserMailIds.php",data:{order_id:order_id},type:'POST', success: function(result){ alert(result); var sampleTags = result.split(',');; console.log(sampleTags); }}); });
Note that the following:
var a = "";
var x = new Array();
x = a.split(",");
alert(x.length);
will alert 1
Pass your comma-separated string into this function and it will return an array, and if a comma-separated string is not found then it will return null.
function splitTheString(CommaSepStr) {
var ResultArray = null;
// Check if the string is null or so.
if (CommaSepStr!= null) {
var SplitChars = ',';
// Check if the string has comma of not will go to else
if (CommaSepStr.indexOf(SplitChars) >= 0) {
ResultArray = CommaSepStr.split(SplitChars);
}
else {
// The string has only one value, and we can also check
// the length of the string or time and cross-check too.
ResultArray = [CommaSepStr];
}
}
return ResultArray;
}
else { ResultArray = [CommaSepStr]; }
after the second if
Here is a function that will convert a string to an array, even if there is only one item in the list (no separator character):
function listToAray(fullString, separator) {
var fullArray = [];
if (fullString !== undefined) {
if (fullString.indexOf(separator) == -1) {
fullArray.push(fullString);
} else {
fullArray = fullString.split(separator);
}
}
return fullArray;
}
Use it like this:
var myString = 'alpha,bravo,charlie,delta';
var myArray = listToArray(myString, ',');
myArray[2]; // charlie
var yourString = 'echo';
var yourArray = listToArray(yourString, ',');
yourArray[0]; // echo
I created this function because split
throws out an error if there isn't any separator character in the string (only one item).
'echo'.split(',')
returns ['echo']
, and ''.split(',')
returns ['']
. You will get an error if you call x.split(',')
when x
is not a string (including when x
is undefined or null), because there is no split
function available for other types.
split
for an undefined object when I wrote up my listToArray function. Thanks for pointing that out...
Upgraded str.split(',')
The simple str.split(',')
doesn't have much smarts. Here are some upgrades for different needs. You can customize the functionality to your heart's content.
const str = "a, b,c, d ,e ,f,,g" const num = "1, 2,3, 4 ,5 ,6,,7.495" const mix = "a, 2,3, d ,5 ,f,,7.495,g" console.log( str.split(',') ) // spaces NOT trimmed, empty values included // ["a", " b", "c", " d ", "e ", "f", "", "g"] console.log( str.split(/[ ,]+/) ) // spaces trimmed, empty values skipped // ["a", "b", "c", "d", "e", "f", "g"] console.log( str.split(/\s*,\s*/) ) // spaces trimmed, empty values NOT skipped // ["a", "b", "c", "d", "e", "f", "", "g"] console.log( num.split(',').map(Number) ) // numbers, empty values default to zero // [1, 2, 3, 4, 5, 6, 0, 7.495] console.log( num.split(/[ ,]+/).map(Number) ) // numbers, skips empty values // [1, 2, 3, 4, 5, 6, 7.495] console.log( mix.split(/\s*,\s*/) .map(x => (x === '') ? '' : (isNaN(Number(x)) ? x : Number(x)) ) ) // mixed values, empty values included // ["a", 2, 3, "d", 5, "f", "", 7.495, "g"]
Using JSON.parse
It may feel like a bit of a hack, but it's simple and highly optimized by most Javascript engines.
It has some other advantages such as support for nested lists. But there are disadvantages, such as requiring the input to be properly formatted JSON.
By using string.replace
similar to how I used string.split
above, you can fix the input. In the first two examples below, I customize how I want empty values handled:
const num = "1, 2,3, 4 ,5 ,6,,7.495" const mix = "a, 2,3, d ,5 ,f,7.495,g" console.log( JSON.parse('['+num.replace(/,\s*,/,',0,')+']') ) // numbers, empty values default to zero // [1, 2, 3, 4, 5, 6, 0, 7.495] console.log( JSON.parse('['+num.replace(/,\s*,/,',')+']') ) // numbers, skips empty values // [1, 2, 3, 4, 5, 6, 7.495] console.log( JSON.parse('['+mix.replace(/(^|,)\s*([^,]*[^0-9, ][^,]*?)\s*(?=,|$)/g,'$1"$2"')+']') ) // mixed values, will ERROR on empty values // ["a", 2, 3, "d", 5, "f", "7.495", "g"]
let str = "January,February,March,April,May,June,July,August,September,October,November,December"
let arr = str.split(',');
it will result:
["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]
and if you want to convert following to:
["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]
this:
"January,February,March,April,May,June,July,August,September,October,November,December";
use:
str = arr.join(',')
Return function
var array = (new Function("return [" + str+ "];")());
Its accept string and objectstrings:
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/
var stringtext = "String, text, I, am"; var stringtextArray = (new Function("return [" + string text + "];")());
result is: SyntaxError: Unexpected identifier
I had a similar issue, but more complex as I needed to transform a CSV file into an array of arrays (each line is one array element that inside has an array of items split by comma).
The easiest solution (and more secure I bet) was to use PapaParse which has a "no-header" option that transform the CSV file into an array of arrays, plus, it automatically detected the "," as my delimiter.
Plus, it is registered in Bower, so I only had to:
bower install papa-parse --save
And then use it in my code as follows:
var arrayOfArrays = Papa.parse(csvStringWithEnters), {header:false}).data;
I really liked it.
A good solution for that:
let obj = ['A','B','C']
obj.map((c) => { return c. }).join(', ')
Shortest
str.split`,`
var str = "January,February,March,April,May,June,July,August,September,October,November,December"; let arr = str.split`,`; console.log(arr);
As @oportocala mentions, an empty string will not result in the expected empty array.
So to counter, do:
str
.split(',')
.map(entry => entry.trim())
.filter(entry => entry)
For an array of expected integers, do:
str
.split(',')
.map(entry => parseInt(entry))
.filter(entry => typeof entry ==='number')
I made php script to convert string to array, and you can run it into your browser, so is easy
<form method="POST">
<div>
<label>String</label> <br>
<input name="string" type="text">
</div>
<div style="margin-top: 1rem;">
<button>konvert</button>
</div>
</form>
<?php
$string = @$_POST['string'];
if ($string) {
$result = json_encode(explode(",",$string));
echo " '$result' <br>";
}
?>
let myString = "January,February,March,April,May,June,July,August,September,October,November,December";
const temp=myString .split(",");
console.log(temp);
Output:- ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]
Very simple you can use the split default javascript function for this.
If the user makes a typo by adding an extra space. You could use something like this.
tags: foo, zar, gar
const stringToArr = (string) => {
return string.trim.split(",");
};
Easiest way to do it:
let myStr = '1, 2, 3, 4, 5, 7, 8';
const stringToArr = (myStr) => {
return myStr.split(',').map(x => x.trim());
};
For an array of strings to a comma-separated string:
let months = ["January","Feb"];
let monthsString = months.join(", ");
Success story sharing
string
has some the richness of the JavaString
.split
will work fine if you are sure you have elements inarray
, if you're expecting data from a server / database you will run into trouble since''.split(',')
has alength === 1
IE:''.split(',') === ['']