swift基础语法(08-数组操作)

获取长度

OC:

NSArray *arr = @[@1, @2, @3];

NSLog(@"%tu", arr.count);

输出结果: 2016-04-01 01:19:54.874 test[12086:2209180] 3

 

swift:

var arr = [1, 2, 3]

print(arr.count)

输出结果:3

 

判断是否为空

OC:

NSArray *arr = @[];

NSLog(@"result = %d", arr.count != 0);

输出结果: 2016-04-01 01:25:14.252 OCTest[12249:2255010] result = 0

        

swift:

var arr = [1, 2, 3]

print(arr.isEmpty)

输出结果: false

 

检索

OC:

NSArray *arr = @[@1, @2, @3];

NSLog(@"%@", arr[0]);

输出结果: 2016-04-01 01:26:46.816 OCTest[12275:2269853] 1

swift:

var arr = [1, 2, 3]

print(arr[0])

输出结果: 1

 

追加

OC:

NSMutableArray *arr =

[NSMutableArray arrayWithObjects:@1, @2, @3, nil];

[arr addObject:@4];

NSLog(@"%@", arr);

输出结果:

2016-04-01 01:28:47.111 OCTest[12297:2286198] (
    1,
    2,
    3,
    4

)

swift:

var arr = [1, 2, 3]
arr.append(4);

print(arr)

输出结果: [1, 2, 3, 4]

 

var arr = [1, 2, 3]
arr += [4]

print(arr)

输出结果: [1, 2, 3, 4]

 

var arr = [1, 2, 3]
arr += [4]

arr += [5,6,7]

输出结果: [1, 2, 3, 4, 5, 6, 7]

 

var arr = [1, 2, 3]
arr += [4]
arr += [5,6,7]
arr += arr[0...3]

print(arr)

输出结果: [1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4]

 

插入

OC:

NSMutableArray *arr =

[NSMutableArray arrayWithObjects:@1, @2, @3, nil];

[arr insertObject:@4 atIndex:0];

NSLog(@"%@", arr);

输出结果:

2016-04-01 01:36:10.450 OCTest[12374:2339079] (
    4,
    1,
    2,
    3

)

swift:

var arr = [1, 2, 3]
arr.insert(4, atIndex: 0);

print(arr)

输出结果: [4, 1, 2, 3]

 

更新

OC:

NSMutableArray *arr =

[NSMutableArray arrayWithObjects:@1, @2, @3, nil];

arr[0] = @8;

NSLog(@"%@", arr);

输出结果:

2016-04-01 01:37:28.482 OCTest[12397:2350177] (
    8,
    2,
    3

)

swift:

var arr = [1, 2, 3]
arr[0] = 8

print(arr)

输出结果: [8, 2, 3]

 

删除

OC:

NSMutableArray *arr1 =

[NSMutableArray arrayWithObjects:@1, @2, @3, nil];

[arr1 removeObject:@1];

NSLog(@"%@", arr1);

NSMutableArray *arr2 =

[NSMutableArray arrayWithObjects:@1, @2, @3, nil];

[arr2 removeLastObject];

NSLog(@"%@", arr2);

NSMutableArray *arr3 =

[NSMutableArray arrayWithObjects:@1, @2, @3, nil];

[arr3 removeAllObjects];

NSLog(@"%@", arr3);

输出结果:

2016-04-01 01:39:49.831 OCTest[12418:2370779] (
    2,
    3
)
2016-04-01 01:39:49.832 OCTest[12418:2370779] (
    1,
    2
)
2016-04-01 01:39:49.832 OCTest[12418:2370779] (

)

swift:

var arr1 = [1, 2, 3]
arr1.removeAtIndex(0)
print(arr1)

var arr2 = [1, 2, 3]
arr2.removeLast()
print(arr2)

var arr3 = [1, 2, 3]

是否保持容量, 如果为true, 即便删除了容量依然存在, 容量是2的倍数

arr3.removeAll(keepCapacity: false)

print(arr3)

print(arr3.capacity)

输出结果:

[2, 3]
[1, 2]
[]

0

 

Range

OC:

NSMutableArray *arr =

[NSMutableArray arrayWithObjects:@1, @2, @3, nil];

[arr removeObjectsInRange:NSMakeRange(0, 2)];

NSLog(@"%@", arr);

输出结果:

2016-04-01 01:43:17.863 OCTest[12441:2396986] (
    3

)

swift:

var arr = [1, 2, 3]
arr.removeRange(Range(start: 1, end: 2))

print(arr)

输出结果: [1, 3]

var arr = [1, 2, 3]
arr.removeRange(0...0)

print(arr)

输出结果: [2, 3]

 

var range = 0...5

print(range)

输出结果: 0..<6