Objective-c - NSArray(NSMutableArray)

Objective-c
- NSArray(NSMutableArray)

//NSArray 初始化
NSArray *arr1 = [NSArray arrayWithObject:@"a" @"b" @"c"];
//NSArray *arr1 = [[NSArray alloc] initWithObjects:@"a", @"b", @"c", nil];
NSLog(@"arr1: %@", arr1);

//效率差
for (int i=0; i<[arr1 count]; i++) {
NSLog(@"arr1 index: %d, obj: %@", i, [arr1 objectAtIndex:i]);
}

//效率高(快速枚举)-官方推荐用
for (NSObject *obj1 in arr1) {
NSLog(@"arr1 index: %ld, obj: %@", [arr1 indexOfObject:obj1], obj1);
}

//NSMutableArray 初始化   arrayWithCapacity(初始化可变数组对象的长度, 后续添加数组会自动扩展)
NSMutableArray *arr2 = [NSMutableArray arrayWithCapacity:2];  //NSMutableArray *arr2 = [[NSMutableArray alloc] initWithObjects:@"a", @"b", "c", nil];

//NSMutableArray 添加对象, addObject
[arr2 addObject:@"1"];
[arr2 addObject:@"2"];
[arr2 addObject:@"3"];
[arr2 addObject:@"4"];
NSLog(@"arr2: %@", arr2);

//NSMutableArray插入对象, insertObjects:<#(NSArray *)#> atIndexes:<#(NSIndexSet *)#>], insertObjects:<#(NSArray *)#> atIndexes:<#(NSIndexSet *)#>
id iObj = @"I am a new one";
[arr2 insertObject:iObj atIndex:2];
NSLog(@"arr2: %@", arr2);

//NSMutableArray 删除对象,
[arr2 removeObject:iObj];
NSLog(@"arr2: %@", arr2);

//NSMutableArray 其他删除方法
//[arr2 removeObjectAtIndex:<#(NSUInteger)#>]
//[arr2 removeObjectsAtIndexes:<#(NSIndexSet *)#>]
//[arr2 removeObjectsInArray:<#(NSArray *)#>]
//[arr2 removeObjectIdenticalTo:<#(id)#>]
//[arr2 removeObjectIdenticalTo:<#(id)#> inRange:<#(NSRange)#>]

//NSMutableArray 替换
[arr2 replaceObjectAtIndex:1 withObject:@"rep one"];
NSLog(@"arr2: %@", arr2);

枚举类型NSEnumerator

NSArray * a1 = [NSArray arrayWithObjects:@"green", @"red", @"blue", nil];
NSEnumerator *e1 = [a1 objectEnumerator];
id obj1;
while (obj1 = [e1 nextObject]) {
NSLog(@"object: %@", obj1);
}

1、创建数组

NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];

2、数组所包含对象个数

[self.dataArray count]

3、获取指定索引处的对象

[self.dataArray objectAtIndex:2]

4、从一个数组拷贝数据到另一数组(可变数级)

//arrayWithArray:
//NSArray *array1 = [[NSArray alloc] init];
NSMutableArray *MutableArray = [[NSMutableArray alloc] init];
NSArray *array = [NSArray arrayWithObjects:
@"a",@"b",@"c",nil];
NSLog(@"array:%@",array);
MutableArray = [NSMutableArray arrayWithArray:array];
NSLog(@"MutableArray:%@",MutableArray);

array1 = [NSArray arrayWithArray:array];
NSLog(@"array1:%@",array1);

5、COPY

NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSArray *oldArray = [NSArray arrayWithObjects:
@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];

NSLog(@"oldArray:%@",oldArray);
for(int i = 0; i < [oldArray count]; i++)
{
obj = [[oldArray objectAtIndex:i] copy];
[newArray addObject: obj];
}
//
NSLog(@"newArray:%@", newArray);
[newArray release];

6、深COPY

//NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSArray *oldArray = [NSArray arrayWithObjects:
@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];
NSLog(@"oldArray:%@",oldArray);
newArray = (NSMutableArray*)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFPropertyListRef)oldArray, kCFPropertyListMutableContainers);
NSLog(@"newArray:%@", newArray);
[newArray release];

7、快速枚举

//NSMutableArray *newArray = [[NSMutableArray alloc] init];
NSArray *oldArray = [NSArray arrayWithObjects:
@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];
NSLog(@"oldArray:%@",oldArray);

for(id obj in oldArray)
{
[newArray addObject: obj];
}
//
NSLog(@"newArray:%@", newArray);
[newArray release];

8、切分数组

NSString *string = [[NSString alloc] initWithString:@"One,Two,Three,Four"];
NSLog(@"string:%@",string);
NSArray *array = [string componentsSeparatedByString:@","];
NSLog(@"array:%@",array);
[string release];

9、从数组合并元素到字符串

NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];
NSString *string = [array componentsJoinedByString:@","];
NSLog(@"string:%@",string);

10、 给数组分配容量

array = [NSMutableArray arrayWithCapacity:20];

11、 在数组末尾添加对象

NSMutableArray *array = [NSMutableArray arrayWithObjects:@"One",@"Two",@"Three",nil];
[array addObject:@"Four"];
NSLog(@"array:%@",array);

12、删除数组中指定索引处对象

NSMutableArray *array = [NSMutableArray arrayWithObjects:@"One",@"Two",@"Three",nil];
[array removeObjectAtIndex:1];
NSLog(@"array:%@",array);

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