Finding a number in an array of strings

Question

I have an array like this

array: [
'Student 1|##|100|@@|Third answer', 
'Student 2|##|10|@@|Third Answer ',
'Student 10|##|50|@@|Third Answer'
]

In it 100 represents the id of the first item of the array, 10 represents the id of the second item of the array and 50 is the id of the third item and so on.

I also have a variable whose value is equal to the id which can be 100 or 10 or 50.

var id = data.myId

I need to check if the id exists in the array.

So if the id is 10 and I do array.includes(id.toString()) it won't return true unless my array is like:

array: [
   'Student 1|##|100|@@|Third answer', 
   'Student 2|##|10|@@|Third Answer ',
   'Student 10|##|50|@@|Third Answer',
   '10'
]

So how do I do that. I am guessing I have to use regex.

gurvinder372 · Accepted Answer · 2017-12-19T09:25:25.467

3

I need to check if the id exists in the array.

Use some, split and check the 3rd item after splitting each item of the string item.

var has10 = array.some( s => s.split( "|" )[2] == "10" );

Demo

var array = [
  'Student 1|##|100|@@|Third answer',
  'Student 2|##|10|@@|Third Answer ',
  'Student 10|##|50|@@|Third Answer'
];
var id = "10";
var hasId = array.some( s => s.split( "|" )[2] == id );

console.log( hasId );

edited Dec 19 '17 at 09:25

answered Dec 19 '17 at 09:12

gurvinder372

66,980
10
72
94

2

Even simpler : `var has10 = array.some( s => s.split( "|" )[2] == id );` – Jeremy Thille Dec 19 '17 at 09:15
1

@T.J.Crowder agree about `some`, removed `filter`. For some reason, `filter` is the first thing I think about :) – gurvinder372 Dec 19 '17 at 09:17
@JeremyThille Yes, I arrived at the similar solution, thanks. – gurvinder372 Dec 19 '17 at 09:17
Yeah, I could see you were editing whilst I was posting this :) – Jeremy Thille Dec 19 '17 at 09:17
1

Or since the OP specifically called out regex: `var rex = new RegExp("^[^|]+\\|[^|]+\\|" + id + "\\|[^|]+\\|[^|]+$"); var has10 = array.some(s => rex.test(s));` :-) But unless a rex is really required, `split` seems better to me. – T.J. Crowder Dec 19 '17 at 09:21
@gurvinder372 Thanks, I had no idea about filter or some... This works... But you can remove the hardcoded 10 and use it like this if you are giving an id variable in the answer `var has10 = array.some( s => s.split( "|" )[2] == id );` – DragonBorn Dec 19 '17 at 09:24
@DragonBorn I have removed the same from demo. – gurvinder372 Dec 19 '17 at 09:25
@gurvinder372 Thanks Accepted – DragonBorn Dec 19 '17 at 09:30

score 1 · Answer 2 · answered Dec 19 '17 at 09:25

1

You can use Array#.find() with this regex \|10\|:

let reg = new RegExp("\\|" + id + "\\|");

It will give you the first element matching the regex or an empty array if there's no match.

var array = [
  'Student 1|##|100|@@|Third answer',
  'Student 2|##|10|@@|Third Answer ',
  'Student 10|##|50|@@|Third Answer'
];
var id = 10;
let reg = new RegExp("\\|" + id + "\\|");
var result = array.find(function(item) {
  return item.match(reg);
});
console.log(result);

answered Dec 19 '17 at 09:25

cнŝdk

31,391
7
56
78

1

Thank you. This will do too. – DragonBorn Dec 19 '17 at 09:33
1

@DragonBorn You are welcome. – cнŝdk Dec 19 '17 at 09:59

Finding a number in an array of strings

2 Answers2