Question

HI, I am a student in college and I am taking a Computer Organization and Machine Language and we are using Assembly Language For x86 Processors. I need to do a lab assigned met , but I am stuck on it, I don't know how to start. can you help me?
The lab says,
" Create an array of characters
initialized that array to 'aaabcccbdddd'
Find out the first apperance of letter 'b' and display its location
In this case, the first apperance would be at number 4."
how do I code this? I am using Microsoft Visual Studio C++.