How could i check if a string contains an element of an array

Question

I have a textarea, and I need to check if this textarea.value contains a string from a string array. Every onkeyup in textarea I call this script. I tried this code, but something went wrong. "@" is ok, but "apple" and "orange" is not. Please help me! Thanks!

var str = document.getElementById("messageArea").value;

var arr = ["@", "apple", "orange"];

for (var i = arr.length - 1; i >= 0; --i) {
    if (str.indexOf(arr[i]) != -1) {
      alert('contains');
   } else {
        alert('not contains');
    }
}

Can you provide a complete example? (input, expected output...) — Idos
– Idos, Commented Jan 31, 2016 at 11:43
Sorry, I forgot this: every onkeyup in textarea i call this script — Gergely Molnár
– Gergely Molnár, Commented Jan 31, 2016 at 11:45
What is the value of str? your problem is not reproducible... The code seems fine — Idos
– Idos, Commented Jan 31, 2016 at 11:47
jsbin.com/vavakoluhe/1/edit?html,js,output . code seems fine — tkay
– tkay, Commented Jan 31, 2016 at 11:49
in my code I turn on or off a button. So when I typing, and I type @, my button is off, it is ok. But when i typing, and i type orange nothing happened. — Gergely Molnár
– Gergely Molnár, Commented Jan 31, 2016 at 11:51

tkay · Accepted Answer · 2016-01-31 12:06:52Z

1

Break the loop when the message contains the substring.

$("#messageArea").on("keyup",function(e){
var str = document.getElementById("messageArea").value;

var arr = ["@", "apple", "orange"];

for (var i = arr.length - 1; i >= 0; --i) {
    if (str.indexOf(arr[i]) != -1) {
      $('#messageBtn').prop('disabled',false);
break;
   } else {
        $('#messageBtn').prop('disabled',true);
    }
}
  });

<!DOCTYPE html>
<html>
<head>
<script src="https://code.jquery.com/jquery-1.11.3.js"></script>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
  <textarea type="text" id="messageArea"></textarea>
  <button disabled id="messageBtn">submit</button>

</body>
</html>

answered Jan 31, 2016 at 12:06

tkay

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Comments

Cosmin Ordean · Accepted Answer · 2016-01-31 12:10:03Z

0

var str = "@ apple orange"; //document.getElementById("messageArea").value;

var arr = ["@", "apple", "orange"];


str = str.trim();

var parts = str.split(" "); // split textarea string by space into another array

for (var part in  parts) { // iterate one every part and check it with your arr variable
  if ( arr.indexOf(parts[part]) != -1 ) {
    alert("found: " + parts[part] );
  } else {
    alert("not contains " + parts[part]);
  }
}

you will get alerts for all 3 elements in the str variable.

answered Jan 31, 2016 at 12:10

Cosmin Ordean

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