Comparing two arrays and pushing the result to new array

Question

I have two arrays that are solely filled with strings. I am trying to compare the values in the strings and then push the strings to an empty array.

goupId = [
{'1','2','3','4'}]
homeGroups = 
[{'2','3', '4','1'}]
sameId =[];

this is my logic

compare: function(groupId, homeGroups) {
                this.groupId.forEach((e1)=>this.homeGroups.foreach((e2)=>{
                    if(e1 === e2){
                        this.sameId.push(e1)
                    }
                }
            ));
            }

I get the error TypeError: Cannot read property 'forEach' of undefined"

Answer 1

You need to drop the this. when referencing groupID and homeGroups as they are not member variables. You can learn more about this here .

Your code will end up looking like this.

compare: function(groupId, homeGroups) {
                groupId.forEach((e1)=>homeGroups.foreach((e2)=>{
                    if(e1 === e2){
                        this.sameId.push(e1)
                    }
                }
            ));
}