object-c 字符串操作方法之－－NSSring以及nsdata，int ,float ,char之间的转换

NSString *tempA = @"123";

NSString *tempB = @"456";

 

1，字符串拼接

NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];

 

2，字符转int

int intString = [newString intValue];

 

3，int转字符

NSString *stringInt = [NSString stringWithFormat:@"%d",intString];

 

4，字符转float

float floatString = [newString floatValue];

 

5，float转字符

NSString *stringFloat = [NSString stringWithFormat:@"%f",intString];6. NSString

 

6.NSString转化为 char *

NSString * str＝ @“Test”;

const char * a =[str UTF8String];

 

7.char * 转化为 NSString

NSString *str=[NSString stringWithCString  encoding:NSUTF8StringEncoding];

 

8.int --> NSData 

int someInt = 1;

NSString *aString = [NSString stringWithFormat:@"%d",someInt];

NSData *someData = [aString dataUsingEncoding:NSUTF8StringEncoding];

[someData writeToFile:[documentsDirectory stringByAppendingString:@"someFile"] atomically:YES];

 

9.NSData --> int

NSData* someData = [NSData dataWithContentsOfFile:[documentsDirectory stringByAppendingString:@"someFile"］;

NSString *aString = ［NSString alloc] initWithData:someData encoding:NSUTF8StringEncoding];

int someInt = [aString intValue];