How to do check if a string is in the array?

#1

Hi!

I’d like to know how could I check if theres a string in an array on Ionic 4, thank you so much

Regards

#2

Hi, @Manel00
You can do something like this,

if (value instanceof Array) {
   var somethingIsNotString = false;
   value.forEach(function(item){
      if(typeof item !== 'string'){
         somethingIsNotString = true;
      }
   })
   if(!somethingIsNotString && value.length > 0){
      console.log('string[]!');
   }
}

First, it will check whether value is array type or not, if it is of array type then it will check each value stored in the value is a string or not if it is not type of string then it will store true in somethingIsNotString.

Hope it helps…!!

#3

It seems quite correctly, maybe something easier?

I’m trying to add on an array a value with kind of includes or contains method, but cannot make it works

if (this.posts.likes.includes(this.myUserId)) {
            this.heartType = 'heart'
        } else {
            this.posts.likes: firestore.FieldValue.arrayUnion(this.user.getUsername())
        }