How to check if a value exists in array with .includes?

February 8, 2022

I know we can use .includes but I’ve been struggling to get it to work with my array. What I want is for my function to check if the value already exists and if it does to remove it from the array.

The value is a string. That value comes from an object that has .name as a property within the object.

0: {id: 190217270, node_id: 'MDEwOlJlcG9zaXRvcnkxOTAyMTcyNzA=', name: '3-Bit-CNC-Starter-Pack'}

1: {id: 187179414, node_id: 'MDEwOlJlcG9zaXRvcnkxODcxNzk0MTQ=', name: 'inb-go'}

I mapped through the data and assigned each button with a value of {d.name}

I am using a button to get the value with this function below

and adding the values to ‘favs’.

const favs = [];

  function checkId(e) {
    if (e.target.value !== "")

      favs.push(e.target.value);

      localStorage.setItem("name", JSON.stringify(favs));
      console.log(favs);
      document.getElementById("favsarray").innerHTML = favs;
    }

console.log
favs

[
    "3-Bit-CNC-Starter-Pack",
    "3-Bit-CNC-Starter-Pack"
]

How can I check to see if the value already exists within the array using .includes?

>Solution :

Just check before push:

function checkId(e) {
    if (e.target.value !== "") {
        if (!favs.includes(e.target.value)) {
            favs.push(e.target.value); 
            // other code here
        }   
    }
}