String Format Specifiers

I’ve been doing a lot of IOS on the weekends lately and today I ran into two problems in regard to String Format Specifiers. I found out that if I don’t use them correctly then xcode gives me runtime errors that look like they are related to bad memory management, but it’s just because I used the wrong specifier. I wrestled with this for a few hours, but someone was able to answer it quickly for me on Stack Overflow.