iOS开发宝典 String用法大全.pdf

iOS 开发宝典:String 用法大全
新手们还在等什么？这是一本属于你的 iOS 开发"字典"，在这里你可以查到字符串、数组、
字典的各式各样的用法与详述。
一、NSString
创建字符串。
1. NSString *astring = @"This is a String!";
创建空字符串，给予赋值。
1. NSString *astring = [[NSString alloc] init];
2.
3. astring = @"This is a String!";
4.
5. NSLog(@"astring:%@",astring);
6.
7. string release];
使用变量初始化
1. NSString *name = @"Ivan!";
2. NSString *astring = [[NSString stringWithFormat:@”My name is %@!”,n
ame]];
3. NSLog(@"astring:%@",astring);
判断是否包含某字符串
检查字符串是否以另一个字符串开头
1. - (BOOL) hasPrefix: (NSString *) aString;
2. NSString *String1 = @"";
3. [String1 hasPrefix:@"NSString"] == 1 ? NSLog(@"YES") : NSLog(@"N
O");
4. [String1 hasSuffix:@".txt"] == 1 ? NSLog(@"YES") : NSLog(@"NO");
是否包含其它字符
1. NSString *astring = [[NSString alloc] initWithString:@"This is a Strin
g!"];
2. Boolean contains = [astring rangeOfString:@”This”].length>0;
从文件读取字符串:
1. initWithContentsOfFile 方法
2. NSString *path = @"";
3. NSString *astring = [[NSString alloc] initWithContentsOfFile:path]
;
4. NSLog(@"astring:%@",astring);
5. [astring release];
写字符串到文件:writeToFile 方法
1. NSString *astring = [[NSString alloc] initWithString:@"This is a Strin
g!"];
2. NSLog(@"astring:%@",astring);
3. NSString *path = @"";
4. [astring writeToFile: path atomic