iOS 判断一个字符串的值是不是 0，

- (BOOL)judgeStringIsZero{
    
    NSString *str = [self copy];
    NSArray *arr = [str componentsSeparatedByString:@"."];
    if (arr.count == 2 ) {//含有小数
        
        while ([str hasSuffix:@"0"]) {
            str = [str substringToIndex:[str length]-1];
        }
        
        if ([str hasSuffix:@"."]) {
            str = [str substringToIndex:[str length]-1];
        }
        
        while ([str hasSuffix:@"0"]) {
            str = [str substringToIndex:[str length]-1];
        }
        
    }else if (arr.count == 1){//不含小数
        while ([str hasSuffix:@"0"]) {
            str = [str substringToIndex:[str length]-1];
        }
    }
    
    if ([str isEqualToString:@"0"] || str.length == 0) return YES;
    
    return NO;
    
}