swift 陣列的新增和刪除

//: a uikit based playground for presenting user inte***ce

import uikit
var array = [(42,"erro2"),(41,"erro1"),(43,"erro3")]
print(array)

同理也有

insert(_:at:) 在指定位置插入乙個元素

insert(contentsof:at)在指定位置插入多個元素

//: a uikit based playground for presenting user inte***ce

import uikit
var array = [(42,"erro2"),(41,"erro1"),(43,"erro3")]
array.insert((40,"error0"),at: 0)
array.insert(contentsof: [(42,"erro2"),(41,"erro1")],at: array.endindex)
print(array)

字串也是collection

字串也是collection element時character型別

["d", "e", "f", "g", "h", "a", "b", "c"]

remove(at:)移除並返回指定位置的乙個元素

removefirst()移除並返回陣列的第乙個元素

popfirst() 移除並返回陣列的第乙個元素（optional）,陣列為空返回nil.

//: a uikit based playground for presenting user inte***ce

import uikit
var chars:[character] = ["a","b","c","d"]
print(chars)
let removedchar = chars.remove(at: 1)
print(removedchar)
print(chars)
let removedchar2 = chars.removefirst()
print(removedchar2)
print(chars)

["a", "b", "c", "d"]

b["a", "c", "d"]
a["c", "d"]

removelist(:)移除後面多個元素

//: a uikit based playground for presenting user inte***ce

import uikit
var chars:[character] = ["a","b","c","d"]
chars.removefirst(2)
print(chars)
chars.removelast(2)
print(chars)

removesubrange(_:)移除陣列中給定範圍的元素

removeall() 移除陣列所有元素

removeall(keepingcapacity:)移除所有元素，保留陣列容量

//: a uikit based playground for presenting user inte***ce

import uikit
var chars:[character] = ["a","b","c","d"]
chars.removesubrange(1...2)
print(chars)
chars.insert(contentsof: "bc", at: 1)
print(chars)
chars.removeall()
print(chars)
print(chars.capacity)
chars.insert(contentsof: "abcd", at: 0)
print(chars)
chars.removeall(keepingcapacity: true)
print(chars)
print(chars.capacity)

["a", "d"]

["a", "b", "c", "d"]
0["a", "b", "c", "d"]
4

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