Matching a string against values of array

Question

i'm trying to make a kind of log in system whereas i'd have a string that would be got from user input and i want to check if that input is in a specific array…

What i got so far:

var name = $(".input").value();
var options = ["option_one", "option_two", "three"];
$(".submit").click(function() {

for(i=0; i < options.lenght; i++){
    if(options[i] == name){
        alert("true")
    }else{
        alert("false")
        }
}


});

Can anyone help me out?

EDIT: CodePen

ibrahim mahrir · Accepted Answer · 2017-02-16 21:12:04Z

2

You can use indexOf like this:

if(options.indexOf(name) != -1){
    alert("valid")
}else{
    alert("false");
}

indexOf will return an index (>=0) from the array where the element is found, -1 otherwise.

answered Feb 16, 2017 at 21:12

ibrahim mahrir

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Comments

kind user · Accepted Answer · 2017-02-16 21:22:37Z

1

Simplier method - use .includes() function.

http://codepen.io/anon/pen/JEVBgN

var name = $(".input").val();
var options = ["option_one", "option_two", "three"];

console.log(options.includes(name) ? 'valid!' : 'invalid!');

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input class='input' value='three'>

edited Feb 16, 2017 at 21:22

answered Feb 16, 2017 at 21:13

kind user

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4 Comments

Angus Over a year ago

always alerts false :C

kind user Over a year ago

@Miguel Check once again. Type three and hit click button.

kind user Over a year ago

@Miguel Exactly. The variables were filled immediately when page was loaded. So the value of input was undefined all the time.

kind user Over a year ago

@Miguel My pleasure :)

Matt Spinks · Accepted Answer · 2017-02-16 21:12:48Z

1

Use the javscript Array.prototype.some() function:

var name = $(".input").value();
var options = ["option_one", "option_two", "three"];
if(options.some(el){
  return el == name;
}){
  alert("valid")
}else{
  alert("false");
}

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

answered Feb 16, 2017 at 21:12

Matt Spinks

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