const simpleArray = ["Сентябрь", "Ежовые рукавицы", "Сепор", "Поручик Ржевский", "Борис"];

​

const objectArrayMutable = [

  {name: "name1", age: 39},

  {name: "name2", age: 75},

  {name: "name3", age: 13}

];

​

const objectArray = [

  {name: "name1", age: 39},

  {name: "name2", age: 75},

  {name: "name3", age: 13}

];

​

function simpleArrayFilter(elem) {

  return !(elem === "Борис" || elem === "Сепор");

}

​

function objectArrayMutatingMap(elem) {

  if (elem.age === 75) {

    delete elem.age;

  }

  return elem;

}

​

function objectArrayMap(elem) {

  let temp = Object.assign({}, elem);

  if (temp.age === 75) {

    delete temp.age;

  }

  return Object.assign({}, temp);

}

​

console.log(

  simpleArray.filter(simpleArrayFilter),

  objectArray.map(objectArrayMap),

  objectArray,

  objectArrayMutable.map(objectArrayMutatingMap),

  objectArrayMutable

);

​