# 3.17 The `vector` type

append()
The append() method appends the number to a vector and returns the new vector.

extend()
The extend() method appends the members of a list or vector to the operand and returns the new vector.

filter()
The filter() method takes a pointer to a function of one argument, . It calls the function for every element of the vector, and returns a new vector of those elements for which tests true.

insert()
The insert() method inserts the number into a vector at position , and returns the new vector.

len()
The len() method returns the number of elements in a vector.

list()
The list() method returns the elements in a vector as a list.

map()
The map() method takes a pointer to a function of one argument, . It calls the function for every element of the vector, and returns a vector of the results.

norm()
The norm() method returns the quadrature sum of the elements in a vector.

reduce()
The reduce() method takes a pointer to a function of two arguments. It first calls on the first two elements of the vector, and then continues through the vector calling on the result and the next item in the vector. The final result is returned.

reverse()
The reverse() method reverses the order of the elements of a vector, and returns the new vector.

sort()
The sort() method sorts the elements of a vector into ascending order, and returns the new vector.