return in a foreach javascript code example

Example 1: javascript forEach return

const list = [{ name: "John", age: 36 },{ name: "Jack", age: 17 }];

// if you just have to FIND an object with a specific value,
// use Array.prototype.find:
const foundHim = list.find( person => person.name === "John" );
console.log( foundHim );

// if you still want to / need to RETURN the object / value
let returnedHim;
list.forEach( person => {
  if ( person.age === 17 ) {
    returnedHim = person;
  }
});

console.log( returnedHim )

Example 2: what foreach method returns in javascript

function double(arr) {
  return arr.forEach(num => num*2);
}

console.log(double([1,2,3,4])) //undefined