Why this code is showing me undefined and type error?

This code is showing error and giving me undefined can anyone pls give me logic for this:

const data = ['1','2','3','4','6'];

const consoleItem = (item, index ,arr) =>{
    console.log(item);
    console.log(index);
    console.log(arr);
} 
data.forEach(consoleItem())

Your syntax was incorrect. The way you have it setup, it only calls consoleItem once and it calls it with no parameters, and the return value is used as a parameter to foreach.

The way I am using it below, consoleItem is acting as a callback to the forEach method and I am passing it the three parameters implicitly given by each iteration of the forEach method.

Try it like this.

const data = ['1','2','3','4','6'];

const consoleItem = (item, index ,arr) =>{
    console.log(item);
    console.log(index);
    console.log(arr);
} 
data.forEach(consoleItem)
//data.forEach((x,y,z) => {consoleItem(x,y,z)})  Same as above