/*
数组定义:
OC:
有值数组
NSArray *arr0 = @[@1, @2, @3];
NSArray *arr1 = [NSArray arrayWithObjects:@1, @2, @3, nil];
NSLog(@"%@", arr1);
空数组
NSArray *arr2 = @[];
NSArray *arr3 = [NSArray array];
NSLog(@"%@", arr3);
不可变数组:NSArray
可变数组:NSMutableArray
*/
//有值数组
var arr0 = [1,2,3]
var arr1: Array = [1,2,3]
var arr2: Array<Int> = [1,2,3]
var arr3: [Int] = [1,2,3]
// var arr4: Int[] = [1,2,3] // 早期写法 已废弃
//空数组
//var arr5 = [] // 已废弃
var arr6 = [Int]()
var arr7 = Array<Int>()
print(arr7)
//不可变数组
let arr8 : [Int] = []
//可变数组
var arr9 : [String] = [String]()
/*
元素类型
OC:
NSArray *arr = @[@1, @"lnj", @1.75];
NSLog(@"%@", arr);
*/
var arr10 = [1,"hjq",1.65] as [Any]
print(arr10)
print(arr10[2])
// 打印结果: [1, "hjq", 1.6499999999999999]
// 1.65
//如果想明确表示数组中存放的是不同类型的数据, 可以使用Any关键字, 表示数组中可以存放不同类型的数据
var arr11:Array<Any> = [1,"hjq",1.75]
print(arr11)
print(arr11[2])
// 打印结果: [1, "hjq", 1.75]
// 1.75
/*
数组操作
1.获取长度
OC:
NSArray *arr = @[@1, @2, @3];
NSLog(@"%tu", arr.count);
*/
var arr12 = [1,2,3]
print(arr12.count)
/*
2.判断是否为空
OC:
NSArray *arr = @[];
NSLog(@"%d", arr.count != 0);
*/
var arr13 = [1,2,3]
print(arr13.isEmpty)
/*
3.检索
OC:
NSArray *arr = @[@1, @2, @3];
NSLog(@"%@", arr[0]);
*/
var arr14 = [1,2,3,4]
print(arr14[0])
/*
4.追加
OC:
NSMutableArray *arr = [NSMutableArray arrayWithObjects:@1, @2, @3, nil];
[arr addObject:@4];
NSLog(@"%@", arr);
*/
var arr15 = [1,2,3]
arr15.append(4)
print(arr15)
var arr16 = [1,2,3]
arr16 += [4]
print(arr16)
arr16 += arr16[0...1] // 也可以借助自己数组元素追加
print(arr16)
/*
5.插入
OC:
NSMutableArray *arr = [NSMutableArray arrayWithObjects:@1, @2, @3, nil];
[arr insertObject:@4 atIndex:0];
NSLog(@"%@", arr);
*/
var arr17 = [1,2,3]
arr17.insert(4, at: 0)
print(arr17)
/*
6.更新
OC:
NSMutableArray *arr = [NSMutableArray arrayWithObjects:@1, @2, @3, nil];
arr[0] = @8;
NSLog(@"%@", arr);
*/
var arr18 = [1,2,3]
arr18[0] = 0
print(arr18)
/*
7.删除
OC:
NSMutableArray *arr = [NSMutableArray arrayWithObjects:@1, @2, @3, nil];
[arr removeObject:@1];
NSLog(@"%@", arr);
NSMutableArray *arr = [NSMutableArray arrayWithObjects:@1, @2, @3, nil];
[arr removeLastObject];
NSLog(@"%@", arr);
NSMutableArray *arr = [NSMutableArray arrayWithObjects:@1, @2, @3, nil];
[arr removeAllObjects];
NSLog(@"%@", arr);
*/
var arr19 = [1,2,3]
arr19.remove(at: 0)
print(arr19)
var arr20 = [1,2,3,4]
arr20.removeLast()
print(arr20)
var arr21 = [1,2,3,4]
arr21.removeFirst()
print(arr21)
var arr22 = [1,2,3,4]
arr22.removeAll(keepingCapacity: true) // 是否保持容量, 如果为true, 即使删除了容量依然存在, 容量是2的倍数
print(arr22)
print(arr22.capacity)
//注意: 如果数组是一个不可变数组不能更新/插入和删除