NSString in Obj-C

一  compare

1 應該用isEqualToString

2 compare

這個可以提供排列。而且還可以進行按照字串的字元長度進行排列。

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);