NSString在工作中常見的用法總結

1、 將字符串切割成數組

 NSString *seasionStr = [[NSString alloc] initWithString : @"春天，夏天，秋天，冬天" ];
 NSArray *seasionArr = [seasion componentsSeparatedByString:@"，"];
 NSString * seasion = [seasionArr objectAtIndex:2];
 NSLog(@"\n  seasionArr的第三個季節是： %@", season);

2、從文件創建字符串

NSString *path = [[NSBundlemainBundle] pathForResource:@"astring.text"ofType:nil];
NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
NSLog(@"astring:%@",astring);

3、compare方法(comparer返回的三種值)

//
NSString *astring01 = @"This is a String!";
NSString *astring02 = @"This is a String!";    
BOOL result = [astring01 compare:astring02] == NSOrderedSame;    //NSOrderedSame判斷兩者內容是否相同
NSLog(@"result:%d",result);    

//
NSString *astring01 = @"This is a String!";
NSString *astring02 = @"this is a String!";
BOOL result = [astring01 compare:astring02] == NSOrderedAscending;    //NSOrderedAscending判斷兩對象值的大小(按字母順序進行比較，astring02大於astring01爲真)
NSLog(@"result:%d",result);

//
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02] == NSOrderedDescending;    //NSOrderedDescending判斷兩對象值的大小(按字母順序進行比較，astring02小於astring01爲真)
NSLog(@"result:%d",result);

4、不考慮大小寫比較字符串

//1.
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 caseInsensitiveCompare:astring02] == NSOrderedSame;    //NSOrderedDescending判斷兩對象值的大小(按字母順序進行比較，astring02小於astring01爲真)
NSLog(@"result:%d",result); 

//2.
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02
options:NSCaseInsensitiveSearch | NSNumericSearch] == NSOrderedSame;    //NSCaseInsensitiveSearch:不區分大小寫比較 NSLiteralSearch:進行完全比較，區分大小寫 NSNumericSearch:比較字符串的字符個數，而不是字符值。 
NSLog(@"result:%d",result);

5、輸出大寫或者小寫字符串

NSString *string1 = @"A String"; 
NSString *string2 = @"String"; 
NSLog(@"string1:%@",[string1 uppercaseString]);//大寫
NSLog(@"string2:%@",[string2 lowercaseString]);//小寫
NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小

6、查找字符串某處是否包含其它字符串

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);

7、substringToIndex: 從字符串的開頭一直截取到指定的位置，但不包括該位置的字符

NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringToIndex:3];
NSLog(@"string2:%@",string2);

8、substringFromIndex: 以指定位置開始（包括指定位置的字符），幷包括之後的全部字符

NSString *string1 = @"This is a string"; 
NSString *string2 = [string1 substringFromIndex:3]; 
NSLog(@"string2:%@",string2);

9、substringWithRange: //按照所給出的位置，長度，任意地從字符串中截取子串

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

10、appendString: 或 appendFormat: //把一個字符串接在另一個字符串的末尾

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);

11、insertString: atIndex: //在指定位置插入字符串

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; 
[String1 insertString:@"Hi! " atIndex:0]; 
NSLog(@"String1:%@",String1);

12、setString:

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"]; 
[String1 setString:@"Hello Word!"];
NSLog(@"String1:%@",String1);

13、replaceCharactersInRange: withString: //用指定字符串替換字符串中某指定位置、長度的字符串

NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"];
NSLog(@"String1:%@",String1);

14、檢查字符串是否以另一個字符串開頭或結尾

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

15、擴展路徑

NSString *Path = @"~/NSData.txt"; 
NSString *absolutePath = [Path stringByExpandingTildeInPath];
NSLog(@"absolutePath:%@",absolutePath);
NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);

16、文件擴展名

NSString *Path = @"~/NSData.txt";
NSLog(@"Extension:%@",[Path pathExtension]);