javascript - check if string is in a array without case sensitive

Question

I want to make a filter. Where if you input a word that is in the 'blacklist' it will tell something. I've got all the code but have a problem.

JS:

input = document.getElementById("input").value;
array = ["1","2","3"];
function filter() {
  if (input == array)
  // I will do something.
  } else {
  // Something too
  }
}

I want to make it so that if the input is a item in the array. That the statement is true. But what is the correct way to do this? Because what I'm doing here doesn't work! Also I want to get rid of the case sensitive! So that if the array has hello in it both hello and Hello are detected.

Sorry if this question is asked before. I searched for it but didn't know what keywords to use.

EDIT 1:

I am changing my question a little bit: I want to check what is in my original question but with some other features.

I also want to check if input has a part of an item in array. So that if the input is hello that helloworld is being detected because is has hello in it. As well as hello or Hello.

http://stackoverflow.com/questions/1181575/javascript-determine-whether-an-array-contains-a-value — Dejan.S, Jun 11 '15 at 14:08
http://stackoverflow.com/questions/12623272/how-to-check-if-a-string-array-contains-one-string-in-javascript — Nagaraj S, Jun 11 '15 at 14:09
I think the keyword can be 'javascript array contains some item', 'javascript check item is in array' or 'javascript input is a item in the array(just copy your word)', it should not be hard to think if you know what you want.... — Surely, Jun 11 '15 at 14:14

score 6 · Accepted Answer · answered Jun 11 '15 at 14:08

6

Use indexOf:

if (array.indexOf(input) > -1)

It will be -1 if the element is not contained within the array.

answered Jun 11 '15 at 14:08

Mathew Thompson

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Thanks! Is there a way to get rid of the case sensitive, so that if I have `hello`. In the array both `hello` and `Hello` are detected? – Roy Berris Jun 11 '15 at 14:12
@Finiox No probems, you'd have to use `map` for case insensitivity and map your values into a temporay array containing the uppercase values, then convert your input to uppercase and do the comparison. It's described in detail here: http://stackoverflow.com/questions/24718349/how-do-i-make-array-indexof-case-insensitive – Mathew Thompson Jun 11 '15 at 14:14

score 1 · Answer 2 · answered Jun 11 '15 at 14:10

1

This code should work:

input = document.getElementById("input").value;
array = ["1","2","3"];
function filter() {
   if (array.indexOf(input) >= 0)
      // I will do something.
    } else {
      // Something too
    }
}

The indexOf Method is member of the array type and returns the index (beginning at 0) of the searched element or -1 if the element was not found.

answered Jun 11 '15 at 14:10

Jan Tchärmän

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13

The more commonly used is `> -1`. I would use this to avoid any further confusion for the OP – Downgoat Jun 11 '15 at 14:12

score 0 · Answer 3 · answered Jun 11 '15 at 14:08

0

I think what you are looking for is

input = document.getElementById("input").value;
array = ["1","2","3"];
function filter() {
  if (array.indexOf(input) !== -1 )
  // I will do something.
  } else {
  // Something too
  }
}

answered Jun 11 '15 at 14:08

iurii

4,142
2
23
28

If fore some reason `indexOf` returned undefined, or null, this will return a false positive – Downgoat Jun 11 '15 at 14:13
from the doc "This method returns -1 if the value to search for never occurs" – iurii Jun 11 '15 at 14:16

javascript - check if string is in a array without case sensitive

3 Answers3