一、Foundation框架中一些常用的类
字符串型:
NSString:不可变字符串
NSMutableString:可变字符串
基本使用
NSMutableString *s1 = [NSMutableString stringWithFormat:@"name is %@",@"程雷"];
// 追加
[s1 appendString:@",age is 23"];
NSRange range = [s1 rangeOfString:@"is"];
// 删除
[s1 deleteCharactersInRange:range];
NSString *s2 = [NSString stringWithFormat:@"name is 李明杰"];
NSString *s3 = [s2 stringByAppendingString:@",age is 29"];
NSLog(@"s1= %@ ,s3 = %@",s1,s3);
集合型:
1)
NSArray:OC不可变数组
NSMutableArray:可变数组
基本使用:
// 错误写法 @[] 只能创建不可变数组
// NSMutableArray *array = @[@"123",@"456"];
// 正确写法
NSMutableArray *array = [NSMutableArray array];
// - (void)setArray:(NSArray *)otherArray;
[array setArray:@[@"123",@"456"]];
NSMutableArray *array = [NSMutableArray arrayWithObjects:@"李明杰",@"程雷",nil];
[array addObject:@"zhouwenchao"];
// 错误写法
//[array addObject: 10];
//这样写也会报错
//[array addObject:nil];
// 删除所有元素
//[array removeAllObjects];
// 删除指定对象
[array removeObject:@"zhouwenchao"];
//[array removeObjectAtIndex:2];
// 输出所有
for (id arr in array) {
NSLog(@"%@",arr);
}
2)
NSSet:
NSMutableSet:
// 可变的
NSMutableSet *s = [NSMutableSet set];
// 添加元素
[s addObject:@"zhouwenchao"];
// 删除元素
//[s removeObject:<#(id)#>];
3)
NSDictiorary
NSMutableDictiorary
基本使用:
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:@"程雷",@"name",@"驻马店",@"address",@"1364340900",@"qq" ,nil];
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
// 添加键值对
[dict setObject:@"zhouwenchao" forKey:@"name"];
[dict setObject:@"民权" forKey:@"address"];
[dict setObject:@"王怡轩" forKey:@"name"];
其它:
NSDate
NSObject