數組遍歷的兩種方式
#import <Foundation/Foundation.h> int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; //也可以用：NSArray *array = [NSArray arrayWithObjects:@"One",@"Two",@"Three",nil]; NSArray* array = [[NSArray alloc] initWithObjects: @"One",@"Two",@"Three",nil]; //nil起結束標志的作用 NSLog(@"%lu", [array count]); //第一種遍歷方法: for(int i = 0; i < array.count; i++) { //如果知道數組里存的對象如本題則可以用NSString接收,如果不知道則可以用id接收 //id obj = [array objectAtIndex:i]; NSString* str = [array objectAtIndex:i]; NSLog(@"%@", str); } //第二種變量方法:快速枚舉 for(NSString* obj in array) { NSLog(@"%@", obj); } NSArray* array2 = [NSArray arrayWithArray:array]; [pool drain]; return 0; }
字符串分割成數組對象與連接
#import <Foundation/Foundation.h> int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; NSString* str = @"one,two,three,four,five"; //分割字符創為數組，下例以“，”分割 NSArray* array = [str componentsSeparatedByString:@","]; for(NSString* obj in array) { NSLog(@"%@", obj); } //鏈接字符串,下例以空格連接 str = [array componentsJoinedByString:@" "]; NSLog(@"%@", str); [pool drain]; return 0; }
運行結果：
2012-06-24 23:18:51.394 demo8[412:707] one
2012-06-24 23:18:51.397 demo8[412:707] two
2012-06-24 23:18:51.398 demo8[412:707] three
2012-06-24 23:18:51.399 demo8[412:707] four
2012-06-24 23:18:51.401 demo8[412:707] five
2012-06-24 23:18:51.401 demo8[412:707] one two three four five
數組的插入：
NSArray只能管理OC的對象，它管理的這些對象可以是不同類型的。
數組對每一個對象具有擁有權。
#import <Foundation/Foundation.h> int main (int argc, const char * argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; //往數組中插入內容 NSMutableArray* array1 = [NSMutableArray arrayWithCapacity:0]; [array1 addObject:@"one"]; NSLog(@"%@", array1); [array1 addObject:@"three"]; //都是插在末尾 NSLog(@"%@", array1); [array1 insertObject:@"two" atIndex:1]; //插入索引為幾的位置 for(NSString* obj in array1) { NSLog(@"%@", obj); } //移除 [array1 removeObjectAtIndex:2]; NSLog(@"%@", array1); [pool drain]; return 0; }