判断是不是空格

前端 ，木办法 只能写一个。第一种想法：我不就是判断 是不是nil就可以了么。结果发现太天真，用户可以输入空格。

-(Bool) isEmpty:(NSString *) str {

    if (!str) {

        returntrue;

    } else {

//A character set containing only the whitespace characters space (U+0020) and tab (U+0009) and the newline and nextline characters (U+000A–U+000D, U+0085).

        NSCharacterSet *set =[NSCharacterSet whitespaceAndNewlineCharacterSet];

 

//Returns a new string made by removing from both ends of the receiver characters contained in a given character set.

       NSString *trimedString = [strstringByTrimmingCharactersInSet:set];

 

        if ([trimedStringlength] == 0) {

            return true;

        } else {

            return false;

        }

    }

}