Check array for values javascript

Question

I have the following in my angular controller

MyUserService.getUserRoles().then(function (data) {
    var userInValidRole = false;
    var role1 = "Role1";
    var role2 = "Role2";

    if ((data.indexOf(role1) > -1) || data.indexOf(role2 ) > -1) {
        userInValidRole = true;
    }

This is working as expected. However I was hoping to do something like:

var validRoles = ["Role1", "Role"];

and then check

    if ((data.indexOf(validRoles) > -1)) {
        userInValidRole = true;
    }

However it is not working as expected - is there something I have done wrong?

var validRoles = ["Role1", "Role"]; last element typo: Role2 — Tushar
– Tushar, Commented Aug 18, 2016 at 14:03
data is already an array and validRoles is another array. That's not how indexOf works. — Tushar
– Tushar, Commented Aug 18, 2016 at 14:04
Just use userInValidRole = data.indexOf(role1) > -1 || data.indexOf(role2) > -1; — Tushar
– Tushar, Commented Aug 18, 2016 at 14:04
data could have multiple roles, right? So if the user has role1 and role3, you're searching the list ['Role1', 'Role3'] to see if any of the elements are equal to the entire list ['Role1', 'Role']. — Eric Dobbs
– Eric Dobbs, Commented Aug 18, 2016 at 14:05
You need to check validRoles.indexOf() for each value in data — Reinstate Monica Cellio
– Reinstate Monica Cellio, Commented Aug 18, 2016 at 14:06

blex · Accepted Answer · 2016-08-19 05:46:16Z

5

You can use Array.prototype.some to check if any role in data is a validRole. And, as @adam-beck suggested below, you cen get rid of the if statement:

var validRoles = ['Role1', 'Role2'],
    userInValidRole = data.some(function(r){ return validRoles.indexOf(r) > -1; });

The advantage of that method is performance. As soon as it finds a correct value, it stops the loop (unlike .forEach(), .map(), .filter()...)

edited Aug 19, 2016 at 5:46

answered Aug 18, 2016 at 14:12

blex

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1 Comment

adam-beck Over a year ago

If userInValidRole should be false otherwise, you could simplfify this: `userInValidRole = data.some(function(r) { return validRoles.indexOf(r) > -1; });

Community · Accepted Answer · 2017-05-23 10:28:39Z

0

Check array intersection mentioned in this post Simplest code for array intersection in javascript

if(data.filter(function(n) {
    return validRoles.indexOf(n) != -1;
}).length > 0){
userInValidRole = true;
}

note: if you want the user to have both roles then check for length == validRoles.length

edited May 23, 2017 at 10:28

CommunityBot

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answered Aug 18, 2016 at 14:08

mkaran

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2 Comments

adam-beck Over a year ago

This works and I did it for quite some time before learning of Array.prototype.some

mkaran Over a year ago

Nice! I didn't know about Array.prototype.some, good to know!

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