IOS之NSSTRING

痛定思痛。 2022-08-05 08:15 172阅读 0赞

//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