ios删除字符串第一位_iOS字符串操作总结

//将NSData转化为NSString

NSString* str = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];

//将NSString 转化为NSData (NSString.h)

- (NSData *)dataUsingEncoding:(NSStringEncoding)encoding;

//在一个字符串中删除一个字符或字符串

[_display deleteCharactersInRange:NSMakeRange(index_of_char_to_remove, 1)];

整数型转换为字符串

NSString *returnStr;

returnStr = [[NSNumber numberWithInt:row] stringValue];

NSString *******************************************************************************************/

//一、NSString

/*----------------创建字符串的方法----------------*/

//1、创建常量字符串。

NSString *astring = @"This is a String!";

//2、创建空字符串，给予赋值。

NSString *astring = [[NSString alloc] init];

astring = @"This is a String!";

[astring release]; NSLog(@"astring:%@",astring);

//3、在以上方法中，提升速度:initWithString方法

NSString *astring = [[NSString alloc] initWithString:@"This is a String!"]; NSLog(@"astring:%@",astring);

[astring release];

//4、用标准c创建字符串:initWithCString方法

char *Cstring = "This is a String!";

NSString *astring = [[NSString alloc] initWithCString:Cstring]; NSLog(@"astring:%@",astring);

[astring release];

//5、创建格式化字符串:占位符(由一个%加一个字符组成)

int i = 1;

int j = 2;

NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];

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

[astring release];

//6、创建临时字符串

NSString *astring;

astring = [NSString stringWithCString:"This is a temporary string"]; NSLog(@"astring:%@",astring);

/*----------------从文件读取字符串:initWithContentsOfFile方法----------------*/ NSString *path = @"astring.text";

NSString *astring = [[NSString alloc] initWithContentsOfFile:path]; NSLog(@"astring:%@",astring);

[astring release];

/*----------------写字符串到文件:writeToFile方法----------------*/ NSString *astring = [[NSString alloc] initWithString:@"This is a String!"]; NSLog(@"astring:%@",astring);

NSString *path = @"astring.text";

[astring writeToFile: path atomically: YES];

[astring release];

/*----------------比较两个字符串----------------*/

//用C比较:strcmp函数

char string1[] = "string!"; char string2[] = "string!";

if(strcmp(string1, string2) = = 0)

{ NSLog(@"1"); }

//isEqualToString方法

NSString *astring01 = @"This is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 isEqualToString:astring02];

NSLog(@"result:%d",result);

//compare方法(comparer返回的三种值)

NSString *astring01 = @"This is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 compare:astring02] = = NSOrderedSame; NSLog(@"result:%d",result);

//NSOrderedSame判断两者内容是否相同

NSString *astring01 = @"This is a String!";

NSString *astring02 = @"this is a String!";

BOOL result = [astring01 compare:astring02] = = NSOrderedAscending; NSLog(@"result:%d",result);

//NSOrderedAscending判断两对象值的大小(按字母顺序进行比较，astring02大于astring01为真)

NSString *astring01 = @"this is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 compare:astring02] = = NSOrderedDescending; NSLog(@"result:%d",result);

//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)

//不考虑大小写比较字符串1

NSString *astring01 = @"this is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame; NSLog(@"result:%d",result);

//NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)

//不考虑大小写比较字符串2

NSString *astring01 = @"this is a String!";

NSString *astring02 = @"This is a String!";

BOOL result = [astring01 compare:astring02 options:NSCaseInsensitiveSearch | NSNumericSearch] = = NSOrderedSame; NSLog(@"result:%d",result);

//NSCaseInsensitiveSearch:不区分大小写比较 NSLiteralSearch:进行完全比较，区分大小写 NSNumericSearch:比较字符串的字符个数，而不是字符值。

/*----------------改变字符串的大小写----------------*/

NSString *string1 = @"A String";

NSString *string2 = @"String";

NSLog(@"string1:%@",[string1 uppercaseString]);//大写

NSLog(@"string2:%@",[string2 lowercaseString]);//小写

NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小

/*----------------在串中搜索子串----------------*/

NSString *string1 = @"This is a string";

NSString *string2 = @"string";

NSRange range = [string1 rangeOfString:string2];

int location = range.location;

int leight = range.length;

NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"Location:%i,Leight:%i",location,leight]]; NSLog(@"astring:%@",astring);

[astring release];

/*----------------抽取子串 ----------------*/

//-substringToIndex: 从字符串的开头一直截取到指定的位置，但不包括该位置的字符 NSString *string1 = @"This is a string";

NSString *string2 = [string1 substringToIndex:3];

NSLog(@"string2:%@",string2);

//-substringFromIndex: 以指定位置开始(包括指定位置的字符)，并包括之后的全部字符 NSString *string1 = @"This is a string";

NSString *string2 = [string1 substringFromIndex:3];

NSLog(@"string2:%@",string2);

//-substringWithRange: //按照所给出的位置，长度，任意地从字符串中截取子串 NSString *string1 = @"This is a string";

NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)]; NSLog(@"string2:%@",string2);

//扩展路径

NSString *Path = @"~/NSData.txt";

NSString *absolutePath = [Path stringByExpandingTildeInPath]; NSLog(@"absolutePath:%@",absolutePath);

NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);

//文件扩展名

NSString *Path = @"~/NSData.txt";

NSLog(@"Extension:%@",[Path pathExtension]);

/******************************************************************************************* NSMutableString *******************************************************************************************/

/*---------------给字符串分配容量----------------*/

//stringWithCapacity:

NSMutableString *String;

String = [NSMutableString stringWithCapacity:40];

/*---------------在已有字符串后面添加字符----------------*/ //appendString: and appendFormat:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

//[String1 appendString:@", I will be adding some character"];

[String1 appendFormat:[NSString stringWithFormat:@", I will be adding some character"]];

NSLog(@"String1:%@",String1); */

/*--------在已有字符串中按照所给出范围和长度删除字符------*/ //deleteCharactersInRange:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 deleteCharactersInRange:NSMakeRange(0, 5)]; NSLog(@"String1:%@",String1);

/*--------在已有字符串后面在所指定的位置中插入给出的字符串------*/

//-insertString: atIndex:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 insertString:@"Hi! " atIndex:0];

NSLog(@"String1:%@",String1);

/*--------将已有的空符串换成其它的字符串------*/

//-setString:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 setString:@"Hello Word!"];

NSLog(@"String1:%@",String1);

/*--------按照所给出的范围，和字符串替换的原有的字符------*/

//-setString:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];

[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"]; NSLog(@"String1:%@",String1);

/*-------------判断字符串内是否还包含别的字符串(前缀，后缀)-------------*/ //01：检查字符串是否以另一个字符串开头

- (BOOL) hasPrefix: (NSString *) aString;

NSString *String1 = @"NSStringInformation.txt";

[String1 hasPrefix:@"NSString"] = = 1 ? NSLog(@"YES") : NSLog(@"NO");

[String1 hasSuffix:@".txt"] = = 1 ? NSLog(@"YES") : NSLog(@"NO");

//02：查找字符串某处是否包含其它字符串

- (NSRange) rangeOfString: (NSString *) aString，这一点前面在串中搜索子串用到过; /******************************************************************************************* NSArray *******************************************************************************************/

/*---------------------------创建数组------------------------------*/ //NSArray *array = [[NSArray alloc] initWithObjects: @"One",@"Two",@"Three",@"Four",nil];

self.dataArray = array;

[array release];

//- (unsigned) Count;数组所包含对象个数；

NSLog(@"self.dataArray cound:%d",[self.dataArray count]);

//- (id) objectAtIndex: (unsigned int) index;获取指定索引处的对象; NSLog(@"self.dataArray cound 2:%@",[self.dataArray objectAtIndex:2]);

/*--------------------------从一个数组拷贝数据到另一数组(可变数级)----------------------------*/

//arrayWithArray:

//NSArray *array1 = [[NSArray alloc] init];

NSMutableArray *MutableArray = [[NSMutableArray alloc] init];

NSArray *array = [NSArray arrayWithObjects: @"a",@"b",@"c",nil]; NSLog(@"array:%@",array);

MutableArray = [NSMutableArray arrayWithArray:array]; NSLog(@"MutableArray:%@",MutableArray);

array1 = [NSArray arrayWithArray:array];

NSLog(@"array1:%@",array1);

//Copy //id obj;

NSMutableArray *newArray = [[NSMutableArray alloc] init];

NSArray *oldArray = [NSArray arrayWithObjects: @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];

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

for(int i = 0; i < [oldArray count]; i++) { obj = [[oldArray objectAtIndex:i] copy]; [newArray addObject: obj]; }

//NSLog(@"newArray:%@", newArray);

[newArray release];

//快速枚举

//NSMutableArray *newArray = [[NSMutableArray alloc] init];

NSArray *oldArray = [NSArray arrayWithObjects: @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];

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

for(id obj in oldArray) { [newArray addObject: obj]; }

// NSLog(@"newArray:%@", newArray);

[newArray release];

//Deep copy

//NSMutableArray *newArray = [[NSMutableArray alloc] init];

NSArray *oldArray = [NSArray arrayWithObjects: @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];

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

newArray = (NSMutableArray*)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFPropertyListRef)oldArray, kCFPropertyListMutableContainers); NSLog(@"newArray:%@", newArray);

[newArray release];

//Copy and sort

//NSMutableArray *newArray = [[NSMutableArray alloc] init];

NSArray *oldArray = [NSArray arrayWithObjects: @"b",@"a",@"e",@"d",@"c",@"f",@"h",@"g",nil];

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

NSEnumerator *enumerator;

enumerator = [oldArray objectEnumerator];

id obj;

while(obj = [enumerator nextObject]) { [newArray addObject: obj]; }

[newArray sortUsingSelector:@selector(compare:)];

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

[newArray release];

/*---------------------------切分数组------------------------------*/ //从字符串分割到数组－ componentsSeparatedByString:

NSString *string = [[NSString alloc] initWithString:@"One,Two,Three,Four"]; NSLog(@"string:%@",string);

NSArray *array = [string componentsSeparatedByString:@","]; NSLog(@"array:%@",array);

[string release];

//从数组合并元素到字符串- componentsJoinedByString:

NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];

NSString *string = [array componentsJoinedByString:@","]; NSLog(@"string:%@",string); /******************************************************************************************* NSMutableArray *******************************************************************************************/

/*---------------给数组分配容量----------------*/

//NSArray *array;

array = [NSMutableArray arrayWithCapacity:20];

/*--------------在数组末尾添加对象----------------*/

//- (void) addObject: (id) anObject;