JS distinguish between objects and primitives in array [duplicate]

Question

I have an update method that should update an item in array:

function update(array) {
  return array.map(item => {
    // item or primitive?
  })
}

What is the best way (in terms of reliability and performance) to distinguish if it's an array of objects or primitive values?

Answer 1

You are use every() and typeof operator

let prim = [1,2,3];
let arrOfObjs = [{a:1},{b:2}];

function isArrayOfObjs(arr){
  return arr.every(x => typeof x === "object");
}

console.log(isArrayOfObjs(prim))   //false
console.log(isArrayOfObjs(arrOfObjs)) //true