NSString详解2--method

1、创建空字符串，给予其赋值

 

2、在上面基础上如果要提升速度，就用 initWithString方法：

 

 

3、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];

4、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]];

// results: 1. This is 2 string!
/*

%i -- integer

%d--double

*/

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

[astring release];


5、创建临时字符串

NSString *astring;

astring = [ NSString stringWithCString : "This is a temporary string " ];

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

6、

/*

------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];

7、

/*

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];    


详细参考：

http://blog.youkuaiyun.com/dirknow/article/details/6604033