Does it mutate 😱

Array.prototype.forEach

No mutation

Description

The forEach() method executes a provided function once per array element.

Array.prototype.forEach ( callbackfn [ , thisArg ] )

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach

Example

var array1 = ['a', 'b', 'c'];

array1.forEach(function(element) {
  console.log(element);
});

// expected output: "a"
// expected output: "b"
// expected output: "c"