Default access modifier in Java - Time & Space Complexity

schedule

Time Complexity: Default access modifier

O(1)

menu_book

Understanding Time Complexity

Let's see how the default access modifier affects the time complexity of code access.

We want to know how the cost of accessing members changes with input size.

code_blocks

Scenario Under Consideration

Analyze the time complexity of accessing a default access modifier member in a class.

class Box {
    int width;  // default access

    int getWidth() {
        return width;
    }
}

public class Main {
    public static void main(String[] args) {
        Box box = new Box();
        box.width = 10;
        System.out.println(box.getWidth());
    }
}

This code defines a class with a default access field and accesses it.

repeat

Identify Repeating Operations

Look for repeated actions that affect time.

• Primary operation: Accessing the width field and calling getWidth().
• How many times: Once in this example, but could be many times if in a loop.

search_insights

How Execution Grows With Input

Accessing a field or method does not depend on input size.

Input Size (n)	Approx. Operations
10	10 accesses if repeated 10 times
100	100 accesses if repeated 100 times
1000	1000 accesses if repeated 1000 times

Pattern observation: Each access is constant time, so total time grows linearly with number of accesses.

cards_stack

Final Time Complexity

Time Complexity: O(1)

This means accessing a default access field or method takes the same time no matter the input size.

chat_error

Common Mistake

[X] Wrong: "Accessing a default access field takes longer as the program grows."

[OK] Correct: Access time depends on the operation itself, not on how many other classes or files exist.

business_center

Interview Connect

Understanding access modifiers helps you reason about code organization and performance clearly, a useful skill in many coding tasks.

psychology_alt

Self-Check

What if the width field was declared private and accessed via a getter method? How would the time complexity change?