NSString in Obj-C

一  compare

1 应该用isEqualToString

2 compare

这个可以提供排列。而且还可以进行按照字符串的字符长度进行排列。

NSString *str= [NSString stringWithFormat:@"100"];     NSString *str2 =[NSString stringWithFormat:@"100"];     NSComparisonResult resul = [str compare:str2 options:NSCaseInsensitiveSearch|NSNumericSearch];     if (resul == NSOrderedSame) {         NSLog(@"They are same!");     }

 

 

二 contain

hasPrefix

hasSuffix

rangeOfString

eg:   

NSRange range = [str rangeOfString:@"2"];     NSLog(@"location:%i length:%i",range.location, range.length);

 

third: NSMutableString

 

NSMutableString *multabstr =[NSMutableString stringWithCapacity:[str length]];     [multabstr appendString:str];     NSLog(@"%@",multabstr);