NSString常见用法 

  1 1、创建常量字符串
  2 NSString *str = @"Hello World!";
  3 
  4 2、创建空字符串，给予赋值
  5 NSString *str = [[NSString alloc] init];
  6 str = @"Hello World!";
  7 [str release];
  8  
  9 
 10 3、initWithString方法
 11 NSString *str = [[NSString alloc] initWithString:@"Hello World!"];
 12 [str release];
 13 
 14 4、用标准c创建字符串:initWithCString方法
 15 char *Cstr = "This is a String!";
 16 NSString *str = [[NSString alloc] initWithCString:Cstr];
 17 [str release];
 18 
 19 5、创建格式化字符串:占位符%
 20 int i = 1;
 21 int j = 2;
 22 NSString *str = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];
 23 [str release];
 24 
 25 6、创建临时字符串
 26 NSString *str = [NSString stringWithCString:"Hello World"];
 27 
 28 7、从文件创建字符串
 29 NSString *path = [[NSBundlemainBundle] pathForResource:@"str.text"ofType:nil];
 30 NSString *str = [[NSString alloc] initWithContentsOfFile:path];
 31 NSLog(@"str:%@",str);
 32 [str release];
 33 
 34 8、用字符串创建字符串，并写入到文件
 35 NSString *str = [[NSString alloc] initWithString:@"This is a String!"];
 36 NSString *path = @"str.text";    
 37 [str writeToFile: path atomically: YES];
 38 [str release];
 39 
 40 9、isEqualToString方法  
 41 NSString *str01 = @"This is a String!";
 42 NSString *str02 = @"This is a String!";
 43 BOOL result = [str01 isEqualToString:str02];
 44 NSLog(@"result:%d",result);
 45 
 46 10、compare方法(comparer返回的三种值)   
 47 //NSOrderedSame判断两者内容是否相同 
 48 NSString *str01 = @"This is a String!";
 49 NSString *str02 = @"This is a String!";   
 50 BOOL result = [str01 compare:str02] == NSOrderedSame;    
 51 NSLog(@"result:%d",result);    
 52  
 53 //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)
 54 NSString *str01 = @"This is a String!";
 55 NSString *str02 = @"this is a String!";
 56 BOOL result = [str01 compare:str02] == NSOrderedAscending;    
 57 NSLog(@"result:%d",result);
 58 
 59 //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)
 60 NSString *str01 = @"this is a String!";
 61 NSString *str02 = @"This is a String!";
 62 BOOL result = [str01 compare:str02] == NSOrderedDescending;    
 63 NSLog(@"result:%d",result); 
 64 
 65 11、不考虑大小写比较字符串
 66 NSString *str01 = @"this is a String!";
 67 NSString *str02 = @"This is a String!";
 68 BOOL result = [str01 caseInsensitiveCompare:str02] == NSOrderedSame;    //NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，str02小于str01为真)
 69 NSLog(@"result:%d",result); 
 70 
 71 NSString *str01 = @"this is a String!";
 72 NSString *str02 = @"This is a String!";
 73 BOOL result = [str01 compare:str02
 74  
 75 options:NSCaseInsensitiveSearch | NSNumericSearch] == NSOrderedSame;   
 76  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。
 77 NSLog(@"result:%d",result);
 78 
 79 12、输出大写或者小写字符串
 80 NSString *string1 = @"String"; 
 81  
 82 NSString *string2 = @"String"; 
 83  
 84 NSLog(@"string1:%@",[string1 uppercaseString]);//大写
 85  
 86 NSLog(@"string2:%@",[string2 lowercaseString]);//小写
 87  
 88 NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小
 89 
 90 13、-rangeOfString: 查找字符串某处是否包含其它字符串
 91 NSString *string1 = @"This is a string";
 92 NSString *string2 = @"string";
 93 NSRange range = [string1 rangeOfString:string2];
 94 int location = range.location;
 95 int leight = range.length;
 96 NSString *str = [[NSString alloc] initWithString:[NSString stringWithFormat:@"Location:%i,Leight:%i",location,leight]];
 97 NSLog(@"str:%@",str);
 98 [str release];
 99 
100 14、-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
101 NSString *string1 = @"This is a string";
102 NSString *string2 = [string1 substringToIndex:3];
103 NSLog(@"string2:%@",string2);
104 
105 15、-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
106 NSString *string1 = @"This is a string";
107 NSString *string2 = [string1 substringFromIndex:3];
108 NSLog(@"string2:%@",string2);
109 
110 16、-substringWithRange: 按照所给出的位置，长度，任意地从字符串中截取子串
111 NSString *string1 = @"This is a string";
112 NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];
113 NSLog(@"string2:%@",string2);
114 
115 17、-stringWithCapacity: 按照固定长度生成空字符串
116 NSMutableString *String;
117 String = [NSMutableString stringWithCapacity:20];
118 
119 18、-appendString: and -appendFormat: 把一个字符串接在另一个字符串的末尾
120 NSMutableString *str1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
121  
122 [str1 appendString:@", I will be adding some character"];
123  
124 [str1 appendFormat:[NSString stringWithFormat:@", I will be adding some character"]];
125  
126 NSLog(@"str1:%@",str1);
127 
128 19、-insertString: atIndex: 在指定位置插入字符串
129 NSMutableString *str1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
130  
131 [str1 insertString:@"Hi! " atIndex:0];
132  
133 NSLog(@"str1:%@",str1);

 

 1 20、-setString:
 2 NSMutableString *str = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
 3  
 4 [str setString:@"Hello Word!"];
 5  
 6 NSLog(@"str:%@",str);
 7 
 8 
 9 21、-replaceCharactersInRange: withString: 用指定字符串替换字符串中某指定位置、长度的字符串
10 NSMutableString *str = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
11  
12 [str replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"];
13  
14 NSLog(@"str:%@",str);
15 
16 
17 22、-hasPrefix: 检查字符串是否以另一个字符串开头
18 NSString *str = @"NSStringInformation.txt";
19  
20 [str hasPrefix:@"NSString"] = = 1 ?  NSLog(@"YES") : NSLog(@"NO");
21  
22 [str hasSuffix:@".txt"] = = 1 ?  NSLog(@"YES") : NSLog(@"NO");
23 
24 
25 23、扩展路径
26 NSString *Path = @"~/NSData.txt";
27  
28 NSString *absolutePath = [Path stringByExpandingTildeInPath];
29  
30 NSLog(@"absolutePath:%@",absolutePath);
31  
32 NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);
33 
34 
35 24、文件扩展名
36 NSString *Path = @"~/NSData.txt";
37  
38 NSLog(@"Extension:%@",[Path pathExtension]);

 

1  // 切割所有的参数
2 NSArray *array = [str componentsSeparatedByString:@"&"];

 

 
posted @ 2013-07-29 18:36  wangzhenxiang  阅读(171)  评论(0)    收藏  举报