尝试打印/调用/或警告数组中的对象：获取未定义

First year @ coding, this is very basic code style for js. Everything I look at to research for help is usually to complex for me to adapt into my basic code. Currently I've got this array I've created, and I'm trying to, in the end game, print out the "course_number, course_title, course_unit" object values onto a page. I'm also trying to modify them as well, but deleting or changing the values. First year @ coding, this is very basic code st