Ruby learning Array

The array size in Ruby can be changed at any time. The elements in the array only save references to objects.

I. Definition

A = array. New ()

A = array. New (5) Create an array of five nil Elements

A = array. New () Create five arrays whose initial values are 1

A = []

A = [1, 2, "a"]

% W (a B c d AB) is used to create a string array, but cannot process strings with spaces

Same as ["a", "B", "C", "D", "AB"]

In addition, Arrays can be used for parallel assignment.

A = 1

B = 2

Can be replaced by a, B = [1, 2]

Ii. Calculation and common methods

<Append, same as ary. Push (OBJ)

+-& | *

Ary. Size/ary. Length

Ary. Concat (other_array) append an array

Ary. Clear

Ary. Delete (OBJ)

Ary. delete_at (INDEX)

Ary. delete_if {| item | block}: delete a qualified element.

Ary. First/ary. Last

Ary. Compact returns a copy that removes Nil

The element of the ary. Flatten array becomes the basic element.

Ary. Index (OBJ) index of the first element equal to OBJ

Ary. insert (index, OBJ) insert

Ary. Join (separator) merges the array into a string linked with separateor

Ary. POP/ary. Shift Delete last and foremost

Ary. Push (OBJ) appending

Ary. Replace (other_array) with Array

Ary. Reverse reverse

Test:

#!/usr/bin/ruby def printResult(args)     print args     puts "" endprintResult [1,2]<<3 printResult [1,2]+[4,5] printResult [1,2]-[1] printResult [1,2,3]&[2,3,4] printResult [1,2,3]|[2,3,4] printResult [1]*5 printResult "#{[1,2].size()} #{[1,2].length()}" printResult [1,2].concat([2]) a=[1,2] a.clear() printResult a.length a=[2,3,4] printResult a.delete(3) printResult a printResult a.delete_at(0) printResult a printResult [1,2,3,4].delete_if{|item| item==1} a=[1,2,3,4,nil] printResult a.compact b=a.compact() a[1]=5 printResult b[1] printResult [1,2,[1,2]].flatten() printResult [1,2,3].index(2) printResult [1,3].insert(1,2) printResult [1,2,3].join("@@@") a=[1,2,3] printResult a.pop() printResult a a.shift() printResult a printResult a.push(2) printResult a.replace([nil,2,3]) printResult a.reverse()

Result:

[1, 2, 3]
[1, 2, 4, 5]
[2]
[2, 3]
[1, 2, 3, 4]
[1, 1, 1, 1, 1]
2 2
[1, 2, 2]
0
3
[2, 4]
2
[4]
[2, 3, 4]
[1, 2, 3, 4]
2
[1, 2, 1, 2]
1
[1, 2, 3]
[Email protected] @ [email protected] @ 3
3
[1, 2]
[2]
[2, 2]
[Nil, 2, 3]
[3, 2, nil]
[Finished in 0.1 s]

Iii. Search, modification, and sorting Iteration

Refer to Ruby's enumerable

Ruby learning Array