Question

What are the array detection non-mutation methods?

Answer 1

The methods which do not mutate the original array but always return a new array are called non-mutation methods. Below are the list of non-mutation methods,

1. filter()
2. concat()
3. slice()

For example, lets take a todo list where it replaces the old array with new one based on status filter,

vm.todos = vm.todos.filter(function (todo) {
  return todo.status.match(/Completed/)
})