數組操作 oc
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[])
{
@autoreleasepool {
//創建數組對象,NSArray不可變數組
//c語言的數組可以存放任何類型的數據,同一個數組只能有同一種數據類型
//oc語言的數組只能存放對象,可以存放任意對象
// [NSNull null] == 空對象
//NSArray *arr = [[NSArray alloc] initWithObjects:@"123",@"345",@"abc", nil];
NSArray *arr1 = @[@"1 2 3", @"345", [NSNull null], @"789"];
NSArray *arr3 = [[NSArray alloc] initWithArray:arr1];
NSLog(@"arr = %@",arr3);
//將c數組轉換爲oc數組對象
//oc不允許將nil插入到數組中,因爲nil作用是數組的結束標記
NSString *carr[10] = {@"123", @"456", @"789"};
NSArray *arr4 = [[NSArray alloc] initWithObjects:carr count:2];
NSLog(@"arr4 = %@",arr4);
//獲取元素個數
NSUInteger count = [arr4 count];
NSLog(@"count = %ld",count);
//獲取指定下標元素
NSLog(@"%@",[arr3 objectAtIndex:1]);
//獲取第一個元素或者最後一個元素
id arrf = [arr3 firstObject];
id arrl = [arr3 lastObject];
NSLog(@"%@ %@",arrf,arrl);
//獲取子集
NSArray *arr2 = @[@"111", @"222", @"333", @"444", @"555", @"666"];
//取出連續範圍的元素作爲子集內容
NSArray *sub1 = [arr2 subarrayWithRange:NSMakeRange(1, 3)];
NSLog(@"sub1 = %@", sub1);
//獲取任意元素作爲子集
//1.列出所需要元素的下標清單
NSMutableIndexSet *indexs = [NSMutableIndexSet indexSet];
//1-1.將要獲取元素的下標寫入清單
for (NSInteger i = 0; i < [arr2 count]; i++)
{
if (i % 2 != 0)
{
[indexs addIndex:i];
}
}
//2.將清單交給數組
//id obj =[arr2 objectAtIndex:0]; //獲取單個元素,返回單個元素
NSArray *sub2 = [arr2 objectsAtIndexes:indexs];//獲取下標清單裏的所有元素,返回一個元素集合(數組)
NSLog(@"sub2 = %@", sub2);
//獲取最長字符串和最小字符串
//快速枚舉
NSArray *arr5 = @[@"123456789", @"222", @"333", @"errr", @"444", @"5", @"666"];
NSInteger maxLength = [arr5[0] length];
NSInteger minLength = [arr5[0] length];
NSString *maxString = nil;
NSString *minString = nil;
for (id obj in arr5) {
if (maxLength <= [obj length]) {
maxLength = [obj length];
maxString = obj;
}
if (minLength >= [obj length]) {
minLength = [obj length];
minString = obj;
}
}
NSLog(@"maxString = %@, minString = %@",maxString,minString);
#if 0
//創建可變數組對象
NSMutableArray *arr1 = [[NSMutableArray alloc] initWithCapacity:30];
NSMutableArray *arr2 = [NSMutableArray arrayWithCapacity:30];
//添加元素
[arr1 addObject:@"123"];
[arr1 addObject:@"456"];
[arr2 addObjectsFromArray:arr1];
[arr2 addObject:@"789"];
[arr2 addObject:@"789"];
[arr2 addObject:@"789"];
NSLog(@"arr1 = %@",arr1);
NSLog(@"arr2 = %@",arr2);
//插入元素
//插入下標的範圍: 0<=index<=count
[arr1 insertObject:@"aaa" atIndex:1];
[arr1 insertObject:@"bbb" atIndex:[arr1 count]];
NSLog(@"arr1 = %@",arr1);
//刪除
[arr2 removeAllObjects];//刪除所有元素
[arr2 removeLastObject];//刪除最後一個元素
[arr2 removeObject:@"789"];//刪除指定對象,會將所有對象刪除
[arr2 removeObject:@"789" inRange:NSMakeRange(1, 2)];//刪除指定範圍中的指定對象
[arr2 removeObjectAtIndex:0];//刪除指定下標的元素
[arr2 removeObjectsInRange:NSMakeRange(2, 2)];//刪除指定範圍中得元素
[arr2 removeObjectIdenticalTo:@"789"];
[arr2 removeObjectIdenticalTo:@"789" inRange:NSMakeRange(2, 1)];
//如果要刪除不連續的元素,則先把要刪除的元素放在一個清單中,然後再刪除該清單
//比如要刪下標爲偶數的
NSMutableIndexSet *indexs = [NSMutableIndexSet indexSet];
for (int i = 0; i < [arr2 count]; i++) {
if (i % 2 == 0) {
[indexs addIndex:i];
}
}
//刪除清單中得元素
[arr2 removeObjectsAtIndexes:indexs];
//修改數組中得內容
[arr2 replaceObjectAtIndex:2 withObject:@"aaa"];
NSArray *arr = @[@"qqqq",@"www",@"ee"];
[arr2 replaceObjectsAtIndexes:indexs withObjects:arr];
// qq, 789, ww, 456, ee
[arr2 replaceObjectsInRange:NSMakeRange(1, 3) withObjectsFromArray:arr];// qq, qq, ww, ee, ee,在指定範圍內,修改數組中得內容。
//交換數組中得內容
[arr2 exchangeObjectAtIndex:1 withObjectAtIndex:3];
//用oc對c語言中得數組進行排序
for (int i = 0; i < [arr2 count]; ++i) {
for (int j = i + 1; j < [arr2 count]; ++j) {
if ([arr2[i] length] > [arr2[j] length]) {
[arr2 exchangeObjectAtIndex:i withObjectAtIndex:j];
}
}
}
NSLog(@"arr2 = %@",arr2);
#endif
}
return 0;
}
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