let listOne = [Bill, Joe, Trever, Neil, Jim, Pam, Michael]
let listTwo = [Petter, Pam, Steven, Jim, Michael, Scott]

I have two lists but I want to create a new list with only the names in both lists.

[Jim, Pam, Michael]

What I did:

I create a nested loop to push each name into a new list

what I need help with:

I feel there is a better way to do this. without having to nest my loops. Perhaps somehow filtering through both lists simultaneously somehow

CodePudding user response：

You could use Array.prototype.reduce, have the callback search the other list, and only insert the name if it is in the other list.

listOne.reduce((prev, cur)=>{
    if(listTwo.includes(cur)){
        prev.push(cur);
    }
    return prev;
});

CodePudding user response：

You can do something like this:

let listOne = [Bill, Joe, Trever, Neil, Jim, Pam, Michael]
let listTwo = [Petter, Pam, Steven, Jim, Michael, Scott]

let result = listOne.filter(item => listTwo.includes(item))

CodePudding user response：

You can make use of Set and filter here. Checking the existence of name in Set is efficient, if you gonna use has method of set.

let listOne = ["Bill", "Joe", "Trever", "Neil", "Jim", "Pam", "Michael"];
let listTwo = ["Petter", "Pam", "Steven", "Jim", "Michael", "Scott"];

const set = new Set(listOne);
const result = listTwo.filter(name => set.has(name));
// or
// const result = listTwo.filter(set.has.bind(set));
console.log(result);

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

const listOne = ["Bill", "Joe", "Trever", "Neil", "Jim", "Pam", "Michael"]
const listTwo = ["Petter", "Pam", "Steven", "Jim", "Michael", "Scott"]

const newList = listOne.filter(item => listTwo.indexOf(item) > -1)
console.log(newList)

<iframe name="sif2" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>