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: Role**2** — Tushar, Aug 18 '16 at 14:03
_data_ is already an array and `validRoles` is _another_ array. That's not how `indexOf` works. — Tushar, Aug 18 '16 at 14:04
Just use `userInValidRole = data.indexOf(role1) > -1 || data.indexOf(role2) > -1;` — Tushar, Aug 18 '16 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, Aug 18 '16 at 14:05
You need to check `validRoles.indexOf()` for *each* value in `data` — Reinstate Monica Cellio, Aug 18 '16 at 14:06

blex · Accepted Answer · 2016-08-19T05:46:16.793

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 '16 at 05:46

answered Aug 18 '16 at 14:12

blex

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1

If userInValidRole should be false otherwise, you could simplfify this: `userInValidRole = data.some(function(r) { return validRoles.indexOf(r) > -1; }); – adam-beck Aug 18 '16 at 14:17

score 0 · Answer 2 · edited May 23 '17 at 10:28

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 '17 at 10:28

Community

1
1

answered Aug 18 '16 at 14:08

mkaran

2,528
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23

This works and I did it for quite some time before learning of `Array.prototype.some` – adam-beck Aug 18 '16 at 14:13
Nice! I didn't know about `Array.prototype.some`, good to know! – mkaran Aug 18 '16 at 14:16

Check array for values javascript

2 Answers2