How to remove undefined from a list of items? - Jquery

myo
August 28, 2022
66 views
2 votes
4 Answers

How to prevent appearing undefined in the output?

var item1 = $(result).find('.item:nth-child(2) a').html(),
    item2 = $(result).find('.item:nth-child(3) a').html(),
    item3 = $(result).find('.item:nth-child(4) a').html(),
    item4 = $(result).find('.item:nth-child(5) a').html();

$('div').html(item1+item2+item3+item4);

Answers

var item1 = $(result).find('.item:nth-child(2) a').html(),
item2 = $(result).find('.item:nth-child(3) a').html(),
item3 = $(result).find('.item:nth-child(4) a').html(),
item4 = $(result).find('.item:nth-child(5) a').html();

item1 = typeof item1 === 'undefined' ? '' : item1;
item2 = typeof item2 === 'undefined' ? '' : item2;
item3 = typeof item3 === 'undefined' ? '' : item3;
item4 = typeof item4 === 'undefined' ? '' : item4;

$('div').html(item1+item2+item3+item4);

- SeyyedKhandon
- August 28, 2022 at 3:42 pm
- 0 votes
0
You can use Nullish coalescing operator to set a default value to prevent undefined values in your code:
```
const item = undefined ?? "";
//output: ""
```
or You can filter them:
```
const items = [undefined, "Hello", undefined, " World!"];
const filtereditems = items.filter(x=>x); 

const joindItems= filtereditems.join(""); 
//output: 'Hello World!'
```
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- RonnyEfronny
- August 28, 2022 at 3:42 pm
- 0 votes
0
You could put them all in an array and then filter it.
```
const array = [item1, item2, item3, item4];
const onlyDefined = array.filter(item => item !== undefined);
```
If you’re not doing anything else with the variables, you could also do it all in chunk, by looping over the numbers 2 through 5.
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