Debug.Log for debugging in Unity - Step-by-Step Execution

Concept Flow - Debug.Log for debugging

Start Program

↓

Code runs

↓

Debug.Log called

↓

Message sent to Console

↓

Developer reads message

↓

Fix or understand code

↓

End or continue

The program runs and when Debug.Log is called, it sends a message to the Unity Console for the developer to see and understand what is happening.

Execution Sample

Unity

void Start() {
    int score = 10;
    Debug.Log("Score is: " + score);
}

This code prints the current score value to the Unity Console when the game starts.

Execution Table

Step	Action	Code Line	Message Sent to Console
1	Start method called	void Start() {
2	Variable score set to 10	int score = 10;
3	Debug.Log called with message	Debug.Log("Score is: " + score);	Score is: 10
4	End of Start method	}

💡 Start method finishes, Debug.Log message shown in Console

Variable Tracker

Variable	Start	After Step 2	After Step 3	Final
score	undefined	10	10	10

Key Moments - 3 Insights

Why do I see the message 'Score is: 10' in the Console?

Because at step 3 in the execution_table, Debug.Log sends the combined string and score value to the Console.

Does Debug.Log change any variables or stop the program?

No, as shown in variable_tracker and execution_table, Debug.Log only prints messages and does not affect variables or program flow.

What if I want to see different values during the game?

You can call Debug.Log anytime with updated values; each call sends a new message to the Console for you to read.

Visual Quiz - 3 Questions

Look at the execution_table, what message is sent to the Console at step 3?

A "Debug.Log called"

B "score = 10"

C "Score is: 10"

D "Start method called"

💡 Hint

Check the 'Message Sent to Console' column at step 3 in execution_table

At which step is the variable 'score' assigned the value 10?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Action' and 'Code Line' columns in execution_table for variable assignment

If you remove Debug.Log line, what changes in the execution_table?

A No message sent to Console at step 3

B Variable 'score' will not be set

C Program will stop immediately

D Start method will not run

💡 Hint

Debug.Log is responsible for sending messages; removing it means no Console output

Concept Snapshot

Debug.Log(message) prints messages to Unity Console.
Use it inside methods to see variable values or program flow.
It does not change variables or stop the program.
Helps find bugs by showing what the program is doing.
Call it anytime to check current values or states.

Full Transcript

When you run a Unity program, Debug.Log lets you print messages to the Console. This helps you see what your code is doing. For example, if you have a variable score set to 10, calling Debug.Log("Score is: " + score) will show "Score is: 10" in the Console. This does not change the score or stop the program. You can use Debug.Log anywhere to check values and understand your program better.