MZLabelSizeHelper.m

/*
  Get UILabel's size for wordwrapping style
*/

+(CGSize)getLabelSizeWordWrapWithString:(NSString*)string 
                                   font:(UIFont*)font
                      constrainedToSize:(CGSize)constrainedSize
{
    if (IOS_VERSION_LESS_THAN_7) {
        
       CGSize size = [string sizeWithFont:font
                        constrainedToSize:constrainedSize
                            lineBreakMode:NSLineBreakByWordWrapping];
        
       return size;
    } else {
        // for iOS7++
        CGRect rect = [string boundingRectWithSize:constrainedSize
                                           options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading
                                        attributes:@{NSFontAttributeName: font}
                                           context:nil];
        return CGRectIntegral(rect).size;
    }
}