is a value in a given list of values using javascript?

Question

How to find out if a given value is among some values? Similar to the IN operator in SQL or what you might expect from sets. Let's suppose set is {male,female,xyz}. I want to find if male is in the set.

c.P.u1 · Answer 1 · 2013-08-23T12:34:54.990

1

The in operator does exist in JavaScript. But it checks whether a property exists on an object.

You can use an object hash or an array:

var values = {male: true, female: true, xyz: true}
var valueToSearch = 'female';

valueToSearch in values; //true

var values = ['male', 'female', 'xyz']

values.indexOf(valueToSearch) !== -1 // true

EDIT: Using a RegExp:

if(pattern.test(search)) {
   //search found
}

edited Aug 23 '13 at 12:34

answered Aug 23 '13 at 12:25

c.P.u1

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var pattern=new RegExp(male|female|xyz); var search="malee"; i want to know search is in pattern or not in terms of true false....in my example answer should be false – user2450833 Aug 23 '13 at 12:28
Please refer to the documentation on RegExp https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp – c.P.u1 Aug 23 '13 at 12:40
i tried with.. var pattern = new RegExp((male|female|xyz),"i"); var search = 'male'; if(pattern.test(search)) { //search found } – user2450833 Aug 23 '13 at 12:41

score 0 · Answer 2 · edited May 23 '17 at 11:49

0

I think what you need is indexOf. Check this example to understand how to use it:

Determine whether an array contains a value

edited May 23 '17 at 11:49

Community

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answered Aug 23 '13 at 12:27

Aashray

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score 0 · Answer 3 · answered Aug 23 '13 at 12:27

0

If you mean in an array you can use indexOf

var find = 'male';
var haystack = ['female', 'male', 'xyz'];

alert((haystack.indexOf(find) >= 0));

answered Aug 23 '13 at 12:27

Oskar Hane

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kmatheny · Answer 4 · 2013-08-23T16:28:36.367

Object

var objNames = {
    "Michigan": "MI",
    "New York": "NY",
    "Coffee": "yes, absolutely"
};

Array

var arrNames = [
    "Michigan", "New York", "Coffee"
]

Function

function isIn(term, list) {
    var i, len;
    var listType = Object.prototype.toString.call(list);

    if (listType === '[object Array]') {
            for (i = 0, len = list.length; i < len; i++) {
                if (term === listType[i]) { return true; }
            }
            return false;
    }

    if (listType === '[object Object]') {
        return !!list[term]; // bang-bang is used to typecast into a boolean
    }

    // What did you sent to me?!
    return false;
}

Usage

var michiganExists = isIn('Michigan', objNames); // true

Note

I didn't use indexOf because the op didn't mention browser support, and indexOf doesn't work with all versions of Internet Explorer (gross!)