Getting the last element of a split string array

Question

I need to get the last element of a split array with multiple separators. The separators are commas and space. If there are no separators it should return the original string.

If the string is "how,are you doing, today?" it should return "today?"

If the input were "hello" the output should be "hello".

How can I do this in JavaScript?

score 1013 · Answer 1 · answered Mar 16 '09 at 18:40

1013

There's a one-liner for everything. :)

var output = input.split(/[, ]+/).pop();

answered Mar 16 '09 at 18:40

Guffa

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Issue here is that pop() also *removes* that element from the array, thereby changing it. – slashwhatever Apr 10 '12 at 15:40
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@Jangla: That's not a problem, as the array is created by the `split` call, it's not kept anyway. The original string is not changed by popping the item from the array. – Guffa Apr 10 '12 at 15:58
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brilliant, all in one go, no need for intermediary var to setup the array...nice – virtualeyes Sep 23 '12 at 08:26
@Guffa Do you know how can I get last two elements of split? – Vitor Oct 16 '15 at 21:52
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@VitorGuerreiro: Yes, you can use the `slice` method: `var output = input.split(/[, ]+/).slice(-2);`. – Guffa Oct 17 '15 at 08:39
What's the purpose of the '+' ? – Mario Levrero Dec 15 '15 at 12:51
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@MarioLevrero: That's a quantifier that means the same as the quantifier `{1,}`, i.e. `[, ]+` matches one or more of the characters in the set (comma and space). It's useful when you want all the words from the string, but when you only want the last word it doesn't make any functional difference, it only reduces the overhead as there will be fewer strings in the array. – Guffa Dec 15 '15 at 15:27

score 158 · Accepted Answer · edited Oct 11 '21 at 09:20

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const str = "hello,how,are,you,today?"
const pieces = str.split(/[\s,]+/)
const last = pieces[pieces.length - 1]

console.log({last})

At this point, pieces is an array and pieces.length contains the size of the array so to get the last element of the array, you check pieces[pieces.length-1]. If there are no commas or spaces it will simply output the string as it was given.

alert(pieces[pieces.length-1]); // alerts "today?"

edited Oct 11 '21 at 09:20

Teocci

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answered Mar 16 '09 at 18:23

Paolo Bergantino

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You could also use `pieces.pop()` to get the last item of your array. – Trent May 11 '18 at 16:02
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is there a way to use this to refer back to str.split() without having to store the variable? – Tanner Jan 06 '19 at 07:29
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`var last = str.split(/[\s,]+/).pop()` – zanderwar May 09 '20 at 09:18

score 107 · Answer 3 · edited May 03 '20 at 17:33

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var item = "one,two,three";
var lastItem = item.split(",").pop();
console.log(lastItem); // three

edited May 03 '20 at 17:33

Pavel

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answered Jun 12 '12 at 18:20

mohawke

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I don't think pop() takes arguments. – Grace Huang Jun 12 '12 at 21:22
@GraceShao: yep. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/pop – aymericbeaumet Jan 23 '15 at 16:59
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But, generically speaking `.split(',').pop()` works for last element on comma separated string. Just sayin' cuz I was misled by Guffa's awesome answer, I just disregarded it because didn't need a regex and thought the trick was there! :P – cregox May 29 '15 at 08:01

score 41 · Answer 4 · edited Oct 11 '21 at 09:23

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Best one ever and my favorite using split and slice

const str = "hello, how are you today?"
const last = str.split(' ').slice(-1)[0]
console.log({last})

And another one is using split then pop the last one.

const str = "hello, how are you today?"
const last = str.split(' ').pop()
console.log({last})

edited Oct 11 '21 at 09:23

Teocci

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answered Dec 11 '18 at 20:08

jithil

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Ah of course. This is a great answer because it doesn't mutate the original +1 – technoY2K Jan 02 '20 at 21:51
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using `.pop()` is still a nice convenience after slice.. no mutation since the accessor method returns a new array. – 4UmNinja Dec 03 '20 at 04:52

score 34 · Answer 5 · answered Dec 18 '18 at 21:13

34

You can also consider to reverse your array and take the first element. That way you don't have to know about the length, but it brings no real benefits and the disadvantage that the reverse operation might take longer with big arrays:

array1.split(",").reverse()[0]

It's easy though, but also modifies the original array in question. That might or might not be a problem.

Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reverse

Probably you might want to use this though:

array1.split(",").pop()

answered Dec 18 '18 at 21:13

Smile4ever

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The `.pop()` method is the best answer I've seen so far. That's why it was created! – Nicholas Porter Feb 20 '20 at 22:43
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I'd strongly advise against reverse() because reversing will be expensive on large arrays. If you don't care about mutation, simply use pop(), otherwise slice(-1)[0]. – wortwart Apr 07 '20 at 14:45
its increasing the time complexity since you have an extra loop to reverse the array. – jithil May 10 '21 at 07:39

score 4 · Answer 6 · answered Nov 24 '21 at 08:20

There are multiple ways to get last elements

let input='one,two,three,four';

let output1 = input.split(',').pop();
console.log('output1 =',output1);

let split = input.split(',');
let output2 = split[split.length-1];
console.log('output2=',output2);

let output3 = input.split(',').reverse()[0];
console.log('output3=',output3);

let output4 = input.split(',').slice(-1)[0];
console.log('output4=',output4);

score 4 · Answer 7 · answered Nov 24 '21 at 11:54

4

This way is easy to understand and very short.

const output = input.split(',').pop().split(' ').pop();

answered Nov 24 '21 at 11:54

David Vicente

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score 4 · Answer 8 · answered Jun 29 '22 at 08:52

The at() method takes an integer value and returns the item at that index, allowing for positive and negative integers. Negative integers count back from the last item in the array.

const str = "how,are you doing, today?";
const last = str.split(/[\s,]+/).at(-1);
console.log({last});

Link to documentation: Array.prototype.at()

score 3 · Answer 9 · answered Feb 01 '12 at 22:06

And if you don't want to construct an array ...

var str = "how,are you doing, today?";
var res = str.replace(/(.*)([, ])([^, ]*$)/,"$3");

The breakdown in english is:

/(anything)(any separator once)(anything that isn't a separator 0 or more times)/

The replace just says replace the entire string with the stuff after the last separator.

So you can see how this can be applied generally. Note the original string is not modified.

score 0 · Answer 10 · edited Jan 16 '17 at 11:04

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var title = 'fdfdsg dsgdfh dgdh dsgdh tyu hjuk yjuk uyk hjg fhjg hjj tytutdfsf sdgsdg dsfsdgvf dfgfdhdn dfgilkj,n, jhk jsu wheiu sjldsf dfdsf hfdkdjf dfhdfkd hsfd ,dsfk dfjdf ,yier djsgyi kds';
var shortText = $.trim(title).substring(1000, 150).split(" ").slice(0, -1).join(" ") + "...More >>";

edited Jan 16 '17 at 11:04

Bart

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answered Jan 16 '17 at 10:59

user7425063

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score 0 · Answer 11 · answered Jul 19 '17 at 18:34

0

You can access the array index directly:

var csv = 'zero,one,two,three'; csv.split(',')[0]; //result: zero csv.split(',')[3]; //result: three

answered Jul 19 '17 at 18:34

tnong

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Hello tnong, welcome to SO! I think this answer does not take the space separator into account as requested in the question. – John-Philip Jul 19 '17 at 19:00
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This answer does not support arbitrary string array length – Nima Soroush Feb 06 '18 at 15:11

Getting the last element of a split string array

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