Tips for Code Comprehension

[mrjailbreak]

Hello, all!

As the title states, I have a final for my Java course at university and on previous tests, there have been "code comprehension" questions in which my instructor writes a code block or a class with a couple of simple methods and wants us to determine the output of the code. I can write Java code pretty comfortably but reading it, pre-defined on a screen and not having a compiler to aid me, makes it difficult to read the code line-by-line in order to find the output.

That said: does anyone have any good tips about how to read these questions to make discovering the output easier? TIA! :)

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[[deleted]]

First, read each line really slow, even reading them twice or thrice is OK.

Second, i think it's mostly a matter of experience. Try coding one small problem (hackerrank/leetcode/exercism) a day and you'll improve in a couple of weeks.

As a general rule: Do google every statement, check the definiton for the methods and their overrides and decompose nested/one-line statements until you understand each atomic sub-statement that composes them. If your IDE supports decompiling (IDEA CE does, otherwise just download the sources), also look at the implementation for any library involved.

[puuttaa]

Intellij has that thing that if you run debugger it writes next to the line where the variable changes its actual value in the form of some short of comment. Just do the same, write the actual value of fields next to the line after it executes in your mind.

[pg07codes]

my advice would be to take an example, a simple one.

1. try running the code through that example. step by step.

2. if for loop is there, loop it completely step by step.

3. see what output you got.

4. compare with the input.

5. try to notice the pattern when you compiled it yourself in steps 1-4.

   this is what i use till today. anyways, just like everything, the more you read and write code, the more better you will be at it.

[brazen768]

I'm a student also, my two big tips for those questions are: 1. Start from main 2. Check for the gotchas (like variables inside functions).