常用基础库objectivec介绍

ObjectiveC基础库介绍NSString创建字符串常见方法3NSString*astring=@"ThisisaString!";NSString*astring=[[NSStringalloc]initWithString:@"ThisisaString!"];

NSString

*astring

=

[NSString

stringWithFormat:@"我的名字：%@

我的年龄：%d

我的邮箱：%s",@“XiaoMing",

25,“"];

NSString

*astring

=

[NSString

stringWithUTF8String:"字符串转换"];

4合并两个字符串int

i

=

100;

char*c

=

“chinasofti";

NSString

*temp

=

@"我是临时字符串";

NSString

*str1

=

[temp

stringByAppendingFormat:@"整型：

%d

字符型

：%s",i,c];

NSString

*str2

=

[temp

stringByAppendingString:temp];

得到字符串长度5NSString*astring=@”HelloWorld”;NSIntegernum=[astringlength]NSLog(@”%d”,num);num=[astringlengthOfBytesUsingEncoding:NSUnicodeStringEncoding];NSLog(@”%d”,num);字符串比较6NSString*str1=@"ThisisaString!";NSString*str2=@"ThisisaString!";BOOLret=[str1isEqualToString:str2];if(ret){ NSLog(@”str1和str2字符串内容相同”);}else{ NSLog(@”str1和str2字符串内容不相同”);}注意，判断两个字符串内容是否相同，一定不可以这样判断：str1==str27NSString*str1=@"ThisisaString!";NSString*str2=@"Thisisastring!";NSComparisonResultret=[str1compare:str2]if(NSOrderedAscending==ret){ NSLog(@”str1小于str2”);}elseif(NSOrderedSame==ret){ NSLog(@”str1等于str2”);}elseif(NSOrderedDescending==ret){ NSLog(@”str1大于str2”);}8NSString*str0=@“icon_background.jpg“;

//字符串以开头比较

if([str0hasPrefix:@“icon"]){NSLog(@"str0字符串以icon开头");}

//字符串以结尾比较

if([str1hasSuffix:@“jpg]){NSLog(@"str0字符串以jpg结尾");}搜索字符串与替换字符串9NSString*str0=@"mynameisXiaoMing";NSString*temp=@"is";NSRangerang=[str0rangeOfString:temp];if(rang.location!=NSNotFound){ NSLog(@“{%d,%d}",rang.location,rang.length);}else{ NSLog(@”没有找到%@”,temp);}

NSString*str=[str0stringByReplacingCharactersInRange:rangwithString:@"啦啦啦……"];NSLog(@"替换后字符串为%@",str);

字符串的截取与大小写改变10NSString*str0=@"mynameisXiaoMing";

//截取字符串起始点到index为4之间的内容

NSString*to=[str0substringToIndex:4];

NSLog(@"to=%@",to);

//截取字符index为2到结尾之间的内容

NSString*from=[str0substringFromIndex:2];

NSLog(@"from=%@",from);

//设置截取字符串的范围，从第二位到第十位

NSRangerang=NSMakeRange(2,10);NSString*strRang=[str0substringWithRange:rang];NSLog(@"rang=%@",strRang);

//设置字符串首字母大写

NSLog(@"str0首字母大写:%@",[str0capitalizedString]);//设置字符串全部内容为大写

NSLog(@"str0大写:%@",[str0uppercaseString]);//设置字符全部内容为小写

NSLog(@"str0小写:%@",[str0lowercaseString]);数值转换doubleValuefloatValueintValueintegerValuelongLongValueboolValue11NSMutableString添加字符串13NSMutableString*str=[[NSMutableStringalloc]initWithString:@"Hello"];[strappendString:@"World!"];NSLog(@"str:%@",str);[strappendFormat:@"1+1=%d",1+1];NSLog(@"str:%@",str);[strrelease];NSMutableString是NSString的子类，它和NSString的主要区别在于可修改删除、插入、替换14NSMutableString*str=[[NSMutableStringalloc]initWithString:@"ThisisaNSMutableString"];[strdeleteCharactersInRange:NSMakeRange(0,5)];NSLog(@"str:%@",str);[strrelease];NSMutableString*str=[[NSMutableStringalloc]initWithString:@"ThisisaNSMutableString"];[strinsertString:@"Hi!"atIndex:0];NSLog(@"str:%@",str);[strrelease];NSMutableString*str=[[NSMutableStringalloc]initWithString:@"ThisisaNSMutableString"];[strreplaceCharactersInRange:NSMakeRange(0,4)withString:@"That"];NSLog(@"str:%@",str);[strrelease];NSArray和NSMutableArrayNSArray数组只可以管理OC对象，不可以管理非OC对象1617[arraycount]:数组的长度。

[arrayobjectAtIndex0]:传入数组脚标的id得到数据对象。

[arrayWithObjects;...]:向数组对象初始化赋值。这里可以写任意对象的指针,结尾必须使用nil。#import<Foundation/Foundation.h>intmain(intargc,constchar*argv[]){@autoreleasepool{NSArray*array=[NSArrayarrayWithObjects:@"a",@”b”,@"c",nil];NSLog(@"arrayCount:%lu",[arraycount]);//遍历数组

for(NSObject*objectinarray){NSLog(@"数组对象:%@",object);}}return0;}NSArray基本用法切割和合并18NSString*string=[[NSStringalloc]initWithString:@"One,Two,Three,Four"];NSLog(@"string:%@",string);NSArray*array=[stringcomponentsSeparatedByString:@","];NSLog(@"array:%@",array);[stringrelease];NSArray*array=[[NSArrayalloc]initWithObjects:@"One",@"Two",@"Three",@"Four",nil];NSString*string=[arraycomponentsJoinedByString:@","];NSLog(@"string:%@",string);NSMutableArray基本用法[NSMutableArrayarrayWithCapacity:0]:初始化可变数组对象的长度，如果后面代码继续添加数组超过长度0以后NSMutableArray的长度会自动扩充，6是自己可以设置的颗粒度。

[arrayaddObject:...]:向可变数组尾部添加数据对象。1920#import<Foundation/Foundation.h>intmain(intargc,constchar*argv[]){@autoreleasepool{

NSMutableArray*muArray=[NSMutableArrayarrayWithCapacity:6];[muArrayaddObject:@"对象1"];[muArrayaddObject:@"对象2"];[muArrayaddObject:@"对象3"];[muArrayaddObject:@"对象4"];[muArrayinsertObject:@"搅局的"atIndex:2];for(NSObject*objectinmuArray){NSLog(@"数组对象:%@",object);}}return0;}删除对象[arrayremoveObject:(id)]:删除数组中指定元素，根据对象isEqual消息判断。[arrayremoveObjectIdenticalTo:(id)]:删除数组中指定元素,根据对象的地址判断[arrayremoveObjectIdenticalTo:(id)inRange:(NSRange)]:在指定范围内删除指定的元素。[arrayremoveObjectAtIndex:(NSUInteger)]:删除数组中指定脚标索引的数据。[arrayremoveObjectsInArray:(NSArray*)]:删除一个数组的元素。2122intmain(intargc,constchar*argv[]){@autoreleasepool{NSString*str1=[[NSStringalloc]init];NSString*str2=[[NSStringalloc]init];NSString*str3=[str1stringByAppendingFormat:@"字符串"];NSString*str4=[str2stringByAppendingFormat:@"字符串"];NSMutableArray*muArray=[NSMutableArrayarrayWithCapacity:6];[muArrayaddObject:@"对象"];[muArrayaddObject:str3];[muArrayaddObject:str4];for(NSObject*objectinmuArray){NSLog(@"数组对象:%@",object);}if([str3isEqual:str4]){NSLog(@"str1isEqualstr2");}if(str3==str4){NSLog(@"str1==str2");}[muArrayremoveObject:str3];for(NSObject*objectinmuArray){NSLog(@"数组对象:%@",object);}[str1release];[str2release];}return0;}23intmain(intargc,constchar*argv[]){@autoreleasepool{NSString*str1=[[NSStringalloc]init];NSString*str2=[[NSStringalloc]init];NSString*str3=[str1stringByAppendingFormat:@"字符串"];NSString*str4=[str2stringByAppendingFormat:@"字符串"];NSMutableArray*muArray=[NSMutableArrayarrayWithCapacity:6];[muArrayaddObject:@"对象"];[muArrayaddObject:str3];[muArrayaddObject:str4];for(NSObject*objectinmuArray){NSLog(@"数组对象:%@",object);}if([str3isEqual:str4]){NSLog(@"str1isEqualstr2");}if(str3==str4){NSLog(@"str1==str2");}[muArrayremoveObjectIdenticalTo:str3];for(NSObject*objectinmuArray){NSLog(@"数组对象:%@",object);}[str1release];[str2release];}return0;}替换24intmain(intargc,constchar*argv[]){@autoreleasepool{NSMutableArray*muArray=[NSMutableArrayarrayWithCapacity:6];[muArrayaddObject:@"对象1"];[muArrayaddObject:@"对象2"];[muArrayaddObject:@"对象3"];[muArrayaddObject:@"对象4"];for(NSObject*objectinmuArray){NSLog(@"数组对象:%@",object);}[muArrayreplaceObjectAtIndex:2withObject:@"字符串替换回来"];for(NSObject*objectinmuArray){NSLog(@"数组对象:%@",object);}}return0;}NSDictionary和NSMutableDictionaryNSDictionary基本用法NSDictionary把数据以键值对的形式储存起来，取值的时候通过key就可以直接拿到对应的值，方便快捷。和NSArray一样，一个词典对象也能保存不同类型的值，词典也分别有不可变词典和可变的词典（NSDictionary与NSMutableDictionary），前者是线程安全的，后者不是。26[NSDictionarydictionaryWithObjectsAndKeys:..]:使用键值对直接创建词典对象，结尾必需使用nil标志结束。[dictionarycount]:得到词典的键值对数量。[dictionarykeyEnumerator]:将词典的所有key储存在NSEnumerator中，类似于Java语言中的迭代器[dictionaryobjectEnumerator]:将词典的所有value储存在NSEnumerator中[dictionaryobjectForKey:key]:通过传入key对象可以拿到当前key对应储存的值。2728intmain(intargc,constchar*argv[]){@autoreleasepool{NSDictionary*dictionary=[NSDictionarydictionaryWithObjectsAndKeys:@"25",@"age",@"张三",@"name",@"男",@"性别",nil];NSLog(@"%lu",[dictionarycount]);NSEnumerator*enumeratorKey=[dictionarykeyEnumerator];for(NSObject*objectinenumeratorKey){NSLog(@"key:%@",object);}

NSEnumerator*enumeratorObject=[dictionaryobjectEnumerator];for(NSObject*objectinenumeratorObject){NSLog(@"value:%@",object);}NSLog(@"keyname的值是:%@",[dictionaryobjectForKey:@"name"]);

}return0;}NSMutableDictionary基本用法[dictionarysetObject:forKey:]:向可变的词典动态的添加数据

[dictionaryremoveAllObjects..]:删除掉词典中的所有数据。

[dictionaryremoveObjectForKey..]:删除掉词典中指定key的数据2930intmain(intargc,constchar*argv[]){@autoreleasepool{NSMutableDictionary*dictionary=[NSMutableDictionarydictionaryWithObjectsAndKeys:@"25",@"age",@"张三",@"name",@"男",@"性别",nil];[dictionarysetObject:@"30名"forKey:@"名次"];

NSLog(@"%lu",[dictionarycount]);NSEnumerator*enumeratorKey=[dictionarykeyEnumerator];for(NSObject*objectinenumeratorKey){NSLog(@"key:%@",object);}

NSEnumerator*enumeratorObject=[dictionaryobjectEnumerator];for(NSObject*objectinenumeratorObject){NSLog(@"value:%@",object);}NSLog(@"key名次的值是:%@",[dictionaryobjectForKey:@"名次"]);[dictionaryremoveObjectForKey:@"名次"];NSLog(@"%lu",[dictionarycount]);}return0;}NSSet和NSMutableSetNSSet基本用法NSSet和NSMutableSet是无序的,但是它保证数据的唯一性。当插入相同的数据时，不会有任何效果。从内部实现来说是hash表，所以可以常数时间内查找一个数据。32[NSSetsetWithSet:(NSSet*)set];用另外一个set对象构造[NSSetsetWithArray:(NSArray*)array];用数组构造[NSSetsetWithObjects:...]:创建集合对象，并且初始化集合中的数值，结尾必需使用nil标志。[setcount];得到这个结合对象的长度。[setcontainsObject:...]:判断这个集合中是否存在传入的对象，返回BOOL值。[setobjectEnumerator]:将集合放入迭代器。[setisEqualToSet:objset]:判断两个集合是否完全相等,返回BOOL值。[setisSubsetOfSet:objset]:判断集合中的所有数据是否都相等与objeset集合中,返回BOOL值。3334intmain(intargc,constchar*argv[]){@autoreleasepool{NSSet*set=[NSSetsetWithObjects:@"25",@"age",@"张三",@"name",@"男",nil];NSSet*set1=[NSSetsetWithObjects:@"25",@"age",@"张三",@"name",@"男",@"性别",nil];

NSLog(@"setcount:%lu",[setcount]);if([setcontainsObject:@"age"]){NSLog(@"set包含age");}if([setisEqualToSet:set1]){NSLog(@"set等于set1");}if([setisSubsetOfSet:set1]){NSLog(@"setisSubsetOfSetset1");}NSArray*array=[setallObjects];NSLog(@"array:%@",array);

NSEnumerator*enumerator=[setobjectEnumerator];for(NSObject*objectinenumerator){NSLog(@"set1里的对象:%@",object);}}return0;}NSMutableSet的基本使用[NSMutableSetsetWithCapacity:6]:创建可变集合对象，并且初始化长度为6。[setaddObject:obj]:向集合中动态的添加对象。[setremoveObject:obj]:删除集合中的一个对象。[setremoveAllObjects]:删除集合中的所有对象。[setunionSet:obj]:向集合中添加一个obj集合的所有数据。[setminusSet:obj]:向集合中删除一个obj集合的所有数据。[setintersectSet:obj]:向集合中删除一个不包含obj集合的所有数据。35intmain(intargc,constchar*argv[]){@autoreleasepool{NSMutableSet*muSet=[NSMutableSetsetWithCapacity:6];[muSetaddObject:@"对象1"];NSSet*set=[NSSetsetWithObjects:@"对象2",@"对象3",@"被企鹅咬了一口",nil];//添加set数据

[muSetunionSet:set];for(NSObject*objectinmuSet){NSLog(@"allnuSet:%@",object);}NSSet*set1=[NSSetsetWit