记录学习过程,做好笔记。
NSDictionary
创建
1 | NSDictionary *dic1 = @{@"apple": @1.5, @"banana": @1.2}; |
读取
1 | for (id key in dic1.allKeys) { |
转换
1 | NSArray *keys = dic2.allKeys; |
写入读取
1 | NSMutableDictionary *dicm1 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@1.5, @"apple", nil]; |
NSSet
创建读取
1 | NSSet *set1 = [NSSet setWithObjects:@1, @2, @3, @4, @1, nil]; |
类型转换
NSString <==> NSNumber
1 | NSString *ageStr1 = @"18"; |
NSString <==> NSArray
1 | NSString *names = @"apple,banana"; |
NSArray <==> NSSet
1 | NSArray *arr = @[@"apple", @"banana", @"apple", @"orange"]; |
NSArray <==> NSDictionary
1 | NSArray *arr1 = @[@"apple", @"banana"]; |
NSData
1 | NSString *str = @"apple"; |
NSError
1 | #import <Foundation/Foundation.h> |