1.1 NSRange

NSRange range = NSMakeRange(2, 4);//location＝2，len＝4

   NSString *str = @"i love oc";

//查找对应的字符串的位置location,length

range = [str rangeOfString:@"love"];

4.2 NSMutableString

// NSMutableString可变字符串

NSMutableString *s1 = [NSMutableString stringWithFormat:@"age is 10"];

[s1 appendString:@"love"];

 NSRange range = [s1 rangeOfString:@"love"];

[s1 deleteCharactersInRange:range];

4.3 NSString

//类方法构造字符串

NSString *str = [NSString stringWithFormat:@"age is %d",10];

NSString *str1 = [NSString stringWithContentsOfURL:url 
encoding:NSUTF8StringEncoding error:nil];

 //对象方法构造字符串

NSString *str1 = [[NSString alloc]initWithContentsOfFile:@"/Users/zhangct/Desktop/1.txt"encoding:NSUTF8StringEncoding error:nil];

 NSString *url = @"file:///Users/zhangct/Desktop/1.txt";

NSString *str2 = [[NSString alloc]initWithContentsOfURL:urlencoding:NSUTF8StringEncoding error:nil];

 //讲字符串写入文件

[str2 writeToFile]

 //常用属性

[s length]

[s characterAtIndex:i]

 //结构体类型转换成字符串

NSStringFromCGRect(<#CGRect rect#>)

NSStringFromCGPoint(<#CGPoint point#>)

4.4 NSString (NSExtendedStringDrawing)

//根据字体计算字符串的显示宽高

NSString *nikeName = @"内涵段子";

NSDictionary *attri = @{NSFontAttributeName: [UIFont systemFontOfSize:13]};

CGSize nikeSize = [nikeName boundingRectWithSize:CGSizeMake(MAXFLOAT, MAXFLOAT) 

options:NSStringDrawingUsesLineFragmentOrigin attributes:attri context:nil].size;

4.5 NSBundle

//获取文件绝对路径

NSString *path = [[NSBundle mainBundle] pathForResource:@"app.plist" ofType:nil];

//加载xib试图文件，返回对象数组

NSArray *objs = [[NSBundle mainBundle] loadNibNamed:@"HMAppView" owner:nil options:nil];

// infoDictionary获取info.plist的字典信息

NSDictionary *dict = [[NSBundle mainBundle] infoDictionary];

// objectForInfoDictionaryKey获取info.plist字典中某一个键值

NSString *versonKey = (__bridge NSString *)kCFBundleVersionKey;

NSString *verson = [[NSBundle mainBundle] objectForInfoDictionaryKey:versonKey];

1.2 NSArray和NSMutableArray

//读取文件内容填充NSArray集合

NSArray *dictArray = [NSArray arrayWithContentsOfFile:path];

 //向数组中每个元素发送SEL消息

array makeObjectsPerformSelector:@selector(<#selector#>)

[self.answerView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];

1.3 NSSet

//获取集合个数

NSLog(@"set1 count :%d", set1.count);

//以数组的形式获取集合中的所有对象

NSArray *allObj = [set2 allObjects];

NSLog(@"allObj :%@", allObj);

//获取任意一对象

NSLog(@"anyObj :%@", [set3 anyObject]);

//是否包含某个对象

NSLog(@"contains :%d", [set3 containsObject:@"obj2"]);

//是否有交集

NSLog(@"intersect obj :%d", [set1 intersectsSet:set3]);

//是否完全匹配

NSLog(@"isEqual :%d", [set2 isEqualToSet:set3]);

//set2是否是set1的子集合

NSLog(@"isSubSet :%d", [set2 isSubsetOfSet:set1]);

1.4 NSMutableSet

//集合元素相减

[mutableSet1 minusSet:mutableSet2];

//只留下相等元素

[mutableSet1 intersectSet:mutableSet3];

//合并集合

[mutableSet2 unionSet:mutableSet3]

//删除指定元素

[mutableSet2 removeObject:@"a"];

//删除所有数据

[mutableSet2 removeAllObjects];

1.5 NSDictionary和NSMutableDictionary

NSDictionary *dict = @{@"name": @"zhangct", @"age": @20};

 NSMutableDictionary *dict = [NSMutableDictionary dictionary];

[dict setValue:@"zhangct" forKey:@"name"];

1.6 NSNumber

NSNumber *num1 = [NSNumber numberWithInt:10];

[num1 intValue];

 NSNumber *num2 = [NSNumber numberWithFloat:1.0];

[num2 floatValue];

 NSNumber *num3;

int age = 20;

num3 = @(age);

num3 = @100;

1.7 NSValue

CGPoint p = CGPointMake(10, 20);

NSValue *value = [NSValue valueWithPoint:p];

 NSLog(@"%@", NSStringFromPoint([value pointValue]));

1.8 NSDate

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

formatter.dateFormat = @"yyyy年MM月dd日 HH时mm分ss秒";

 NSDate *date = [NSDate date];

NSLog(@"%@", [formatter stringFromDate:date]);

4.6 NSObject

4.6.1 NSObject

[self performSelector:@selector(onClick:value1:) withObject:nil withObject:nil];

performSelector是执行self对象中的onClick:value1:方法，最多支持传递2个参数.

4.6.2 NSObject(NSDelayedPerforming)

//播放完毕后延迟1秒执行释放内存

[self.tom performSelector:@selector(setAnimationImages:) 
withObject:nil afterDelay:self.tom.animationDuration + 1.0f];

4.6.3 NSObject(NSKeyValueCoding)

//单个赋值

[self setValue:dict[@"answer"] forKey:@"answer"];

[self setValue:dict[@"title"] forKey:@"title"];

 //ForKeyPath取值，返回Person的car name

[p valueForKeyPath:@"car.name"]

 //ForKeyPath取值返回title数组

carsGroups valueForKeyPath:@"title"

//字典转模型，使用此方法要保证属性名称和字典的key同名

[self setValuesForKeysWithDictionary:dict];

 //模型转字典

NSDictionary *dict = [p dictionaryWithValuesForKeys:@[@"name", @"age"]];

4.6.4 NSObject(UINibLoadingAdditions)

//当xib文件加载完毕后执行

- (void)awakeFromNib;

4.8 NSIndexPath

//根据分组和行号初始化对象

NSIndexPath *indexPath = [NSIndexPath indexPathForRow:10 inSection:0];

 //返回分组

indexPath.section

 //返回行号

indexPath.row